Recent Works on the Diptera of Northern Europe

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Recent Works on the Diptera of Northern Europe  (1855) 
by Alexander Henry Haliday

Recent Works on the Diptera of Northern Europe 1855 Review. Recent works on the Diptera of Northern Europe. Natural History Review (Proc.) 2: 49-61

RECENT WORKS ON THE DIPTERA OF NORTHERN EUROPE. 1. ZETTERSTEDT, INSECTA LAPPONICA, ETC. 1 Tom. Folio; Lipsise, 1840. 2. ZETTERSTEDT, DIPTERA SCANDINAVIA, ETC. 11 Tomi, 8vo. Lundse, 1842-1852. 3. STAEGER, SYSTEMATISE FORTEGNELSE OVER DE i DANMARK FUNDNE DIPTERA, samt DANSKE DOLICHOPODER, o.s.v. i Kroyers Naturhistorisk Tidsskrift, Iste Raekke, lste-4de Bind, 1837-1844. 4. STENHAMMAR, FORSOK TILL GRUPPERING OCH REVISION AF DE SVENSKA EPHYDRINAE, i Kongl. Sv. Vet. Akademiens Handlingar for aar 1843. 5. WAHLBERG,DAHLBOM, BOHEMANN NYA SVENSKA DIPTERA) i detsamma, och Oefversigt af K. Sv. Vet. Akad. Fbrhandlingar, aatskiliga aar. THE extent of the field which Entomology appropriates, even since the Crustacea and Arachnida have been detached from it, has made its literature already voluminous, though barely of the growth of a century, and promises an increase in proportion for a long time to come. Apart from the common domains of anatomy and physiology, the history and classification of its countless species, probably outnumbering all the other denizens of the land, are enough to occupy Reaumurs and Degeers, if such there should be, yet unborn. Probably, in consequence, a somewhat partial and one-sided character has been impressed upon the science with most who have pursued it with predilection ; so that the results to be looked for from the study of the endlessly-diversified, yet closely-linked, modifications of that onem well marked type of organization, have scarcely yet redounded to the benefit of biological science in general. And not only has Entomology been treated as if it were an independent branch, but the attention both of collectors and systematists has been much confined to one or two orders out of the whole. Indeed, reasons may be easily found for the preference so generally given to the Lepidoptera and Coleoptera; and the classification of the latter has now arrived at such a stage, that the study of it may be considered as a preliminary training for that of the other orders. But, this point attained, we are glad to see increasing attention of late directed towards the sometime slighted clearwings of collectors, as preparing the way for broader views of the class of insects, in itself as a whole, and in its relations to the rest of animated nature. Each of the other orders, meantime, may, invite a study as particular as the Coleoptera have received, and some of them, perhaps, will afford a field as ample. Local Faunas, Monographs, the collections of voyagers, all have their use in building up parts of the unfinished fabric ; and the productions of our own country naturally will occupy the greatest number of students at home. But, with the exception of the two orders before named, the British collector quickly finds himself at a loss for any ready means of determining even the names of the puny myriads that flit or creep, dive or burrow, on every side about him. In default of manuals devoted to the productions of our own country, we may look abroad, next, to those which describe the insects of the nearest mainland, from which chiefly the island Fauna seems derived, a colony diminished by the broken continuity of land, and the lower summer temperature of a seagirt shore. The Fauna of France, whose territorial limits lean on the snowy buttresses of the Alps and Pyrenees, on either hand, flanking a gulf of the Mediterranean, whither many of the insects seem as if transmitted, with the hot winds, from the African coasts opposite, is enriched with Alpine and southern forms wholly strange to us. But a comparison of the Coleoptera of each, points to the inference that the British insect Fauna might almost be presented as an extract from that of neighbouring France ; while the species deficient in the latter may mostly be found in the Scandinavian Fauna, along with the great majority common to the three countries. Passing beyond that order and the Lepidoptera, the materials for such a comparison have been hitherto more imperfect.We have coupled together, at the head of this article, the chief contributions to the Dipterous Fauna of Scandinavia, which have appeared since Meigen's Systematic Description of the Diptera of Europe was completed. The impulse given by that classical work to the study of this order has tended to antiquate itself in some degree, as Meigen's terse and scientific definitions became inadequate, amid the additions made by the industry of his scholars. Among those who have contributed to such a revolution, the Swedes may justly claim a foremost place ; and we would scarcely dispute Bohemann's judgment of the great work of Zetterstedt now concluded, that no other country can show a descriptive catalogue of its Diptera so complete and accurate as Sweden possesses.* Restricted to the limits of the Scandinavian and Jutish peninsulas and islands, it does not affect the character of a DIPTEROLOGIA EUROPAEA, as Oken has ventured to style it.f But for the determination of the British species of Diptera in general, we have, up to this time, no book of reference as use-

  • Aarsberattelse for 1847-8. t Isis, 1848, 696.

ful and complete. The other essays, which we have coupled with it, having been chiefly incorporated in this comprehensive work, we shall have little occasion to review them individually, but some notice of them seemed necessary towards a general summary of the contributions to the literature of the order, which have proceeded from this quarter, since the last additions were engrafted on the system by Meigen.Staeger commenced, in 1838, publishing a catalogue of the Diptera of Denmark, in Kroyer's N. H. Journal, with descriptions of the new species only, of which the number was not inconsiderable. We owe to him the institution of two new genera, Ptiolina and Boletina. Having gone through the Nemocera on this plan, and commenced a Monograph of the Dolichopidae, of which only the species of Dolichopus, Sybistroma, and Orthochile were given in detail, he transferred the materials for the rest to the behoof of Zetterstedt's work, which his communications chiefly have rendered a Fauna for both countries.Stenhanmmar has produced a very accurate and complete description of the Ephydrini of Sweden, the number of which he has much more than doubled. His generic arrangement deserves the highest praise, and the changes which Zetterstedt has made, while adopting it in the main, cannot be called improvements. His careful delineation also of the external anatomy of these insects has both laid the grounds for a better characteristic of the genera and species, and supplied materials for a more precise glossary of the parts. We think the term praelabrum, which he has introduced, superfluous,the part denoted corresponding to the epistoma in other orders,where it is separated by a distinct suture from the hypostoma or face. We gladly look for a promised Monograph of the Sphaerocerini from the same pen, expecting that an enlarged acquaintance with the literature of Entomology will exclude from it such nominally new, but, in fact, previously described, species and genera, as have gone to swell the synonyms among the Ephydrini.Of the shorter essays in the Transactions and Proceedings of the Swedish Academy, in which many species have been described originally, those by Wahlberg are the most important, as containing the characters of several new genera, Thinophilus, Psairoptera, Amphipogon, Lobioptera, Selachops.Zetterstedt's earlier work, INSECTA LAPPONICA, opens with a very interesting sketch of the distribution of insects on the several stages of ascent of the Lappish Alps. The outline, drawn with a masterly hand by Heer," On the Highest Limits of Animal and Vegetable Life on the Swiss Alps" has since been filled up, in part, for the zones -of the Alps, the Pyrenees, the Riesengebirge, and Caucasus, respectively, by Ghiliani, Dufour, Kiesenwetter, Kolenati, and others ; but scarcely one of them has produced a picture more full of life, or rich in details, than Zetterstedt, the earliest of the list. The greatest number of the new Dipterous genera, and a large proportion of new species, were characterized in this volume ; but we propose to treat all such together in our examination of the DIPTERA SCANDINAVIAE. This great work, a monument both of untiring industry, erudition, and acute discrimination, is comprised in eleven 8vo volumes, which average above four hundred pages each ; and the publication, commenced at the author's own expense, and afterwards worthily sustained by the public purse, has extended over a period of ten years. After a short preface, and list of works cited, an hundred and three pages are given to the analysis and characteristic of the families and genera. A final index of one hundred and ninety-two pages, containing the synonyms, as well as the generic and trivial names of the text, affords every facility for reference that can be desired. The specialities, analysis, description, and history of the species, with supplementary characters of the genera (two hundred and eighty-five in number), fill nearly four thousand two hundred and fifty pages, giving for each of the 3,462 species described, after all deductions, a good deal more than a page on the average. Of this number, 1,585 purport to have been first described in one or other of the books we have titled, making the proportion rather more than five new species to six previously included among the European Diptera of Meigen ; and of these last, Fallen had recorded but 845, where Zetterstedt has 1,260 in the corresponding families ; so largely has the older stock of Fallen and Fries been added to by the author's own travels in Lapland, and by the communications of Dahlbom, Wahlberg, Anderson, and Skogmann, from the same source; of Liebke, in Norway; Sahlberg, Nylander, and Mannerheim, in Finland; Staeger, Schiodte, Drewsen, Boje, Jacobsen, and Westermann, in Denmark ; besides a list of about twenty correspondents in the Swedish provinces, including the honoured names of Schonherr and Bohemann. When will our own islands furnish such help to any one who may undertake for them a task like that Zetterstedt has achieved for his country ? Particular attention has been paid to the geographical distribution of the species, and various localities are assigned for most of them ; so that the names of some of these correspondents recur as authorities almost in every page. These volumes of Zetterstedt's are the more available to the British student, as they are wholly written in Latin fair, entomological Latin ; a quality which, without pretending to classical nicety, we are not disposed to undervalue, with the recollection fresh of the curious dialects that certain naturalists, on either side of the Alps, have muffled in the folds of the toga. Erichson has given a recipe for such cases when, criticising a compatriot, he goes on to say " Our western neighbours, also, in their natural history works, favour us pretty often with a Latin which can only be deciphered through the medium of a literal retranslation into the vernacular idiom of the writers." The closer affinity of the Runic idioms to the English may render us less sensitive to isms from this source than we are to the German, French, or Italian dialects of Latin. Certainly we have found no occasion for a Latin-Swedish dictionary, in order to understand Zetterstedt's descriptions. We must demur, however, when he calls in question subsultans of Linnaeus, or borrows such a superfluous barbarism as anciennetas, foreign alike to the vocabulary of the great master, and of his classical models. But these are the rare and pardonable slips of a style sufficiently correct in general. To us the least satisfactory portion of Zetterstedt's work is the composition and arrangement of the families.Commencing with Tabanus, the series of the Brachycera is made to end in Phora, followed by the Coriaceae, which again the Nemocera succeed.Here the interposition of Phora and the Coriaceae excludes all thoughts of a natural transition between the two great sections of the order. The system of the Diptera Scandinavia is avowedly an artificial one; but viewed simply as such, seems not to fulfil the end so well as to compensate for the disregard of natural affinities. Zetterstedt, in grateful deference to the authority of his illustrious master in Entomology, has retained the arrangement and names of Fallen's older system to a great extent, when, perhaps, his unbiassed judgment might have accorded better with the more recent systems of Meigen or Macquart. But in the Nemocera also, where he had not that precedent to constrain him, and his classification is more original, some of the families appear as far from natural groups. Perhaps the most signal instance is that which Schaum has already singled out the Ryphii, in which Rhyphus, the typical genus, possessing three equal and equidistant ocelii, an ambient vein, and normal system of venation, stands associated with Ceroplatus and Cordyla, two genera transferred from the Mycetophilinae, a family whose characters are nearly the opposite of those ; while the larvae of the two are no less different, that of Rliyphus being amphipneustic,* those of the Mycetophilinae peripneustic.f Another genus, Pachyneura, having three ocelli, and wanting the suture of the mesonotum that is characteristic of the Tipulides, with which it is ranked by Zetterstedt, should probably also be referred to the

  • With anterior and posterior spiracles only. f With intermediate spiracles also.

Mycetophilinae, with some of which it closely agrees in the venation. The latter family, again, should be rid of Corynocera a genus whose affinity to his Chironomii has not entirely escaped Zetterstedt's observation, and to us appears unquestionable. In the section Brachycera, again, the conjunction of Lonchoptera with Phytomyza in one family (Phytomyzides) seems unaccountable, except on the ground of Fallen's preponderating authority, all other modern systematists having removed the former genus entirely from the Muscidae. This great family has been carved by Zetterstedt, following Fallen, into a number of groups, which, though here denominated families, cannot, in respect of characters, be accounted co-ordinate with the other families of this order, however the multitude of species to be grouped may recommend such a plan in a system professedly artificial. But, indeed, the subdivisions of this family have been so variously treated, that we do not venture to criticise closely the order or limits of Zetterstedt's corresponding groups. Only the Haematomyzides may be specified as a merely artificial assemblage of members taken from three different natural groups ; Siphona being closely related to Tachina, Prosena to Dexia, and Stomoxys to Musca. We are compelled to regard it as a retrograde step, that Zetterstedt has fused again so many modern genera into one vast one as in the cases of Tachina, Anthomyia, Aricia, the last two being distinguished from each other merely by the colour of the legs. The carefully - constructed analytical tables of the species, given with each at least of the more extensive genera, do, however, remedy, in a great degree, the inconveniences of such a fusion ; nor can we attribute the rejection of so many genera to any indolence, since in the notes he has been at the pains of referring every species he has described of these to its appropriate place in some one of the genera adopted by Meigen in his supplementary volume. The descriptions of the species in the DIPTERA SCANDINAVIA we have found in general as clear as they are full ; and we must commend, in particular, the simple phrases by which he has, in many instances, delineated the varying venation of the wings without the help of figures. Having expressed dissatisfaction with the families he has given, we shall rather follow the arrangement proposed in the first volume of the INSECTA BRITANNICA, and refer the new genera we have to notice to their places in the families according to it. MYCETOPHILIDAE Pachyneura, venation not very unlike Platyura, antennae filiform (18-jointed?), palpi 4-jointed, lateral spines of tibia 3 very slight; one species P. fasciata, 9-11 lines long; Lapland and N. Sweden about rotten trunks of trees. Boletina Stg., for the species of Leja Mg., in which the forks of the two brachial veins are equally distant from the base of the wing. CHIRONOMIDAE Corynocera, wings adiaphauous, with four or five very obsolete veins, the tip armed with a long curved bristle, which is triple in the female, antennae 12-jointed, the first joint short and stout, the last oblong and thickened, the intermediate joints small, globose, and compact; one species C. ambigua, 1-2 lines long, found on the shore of a lake in Tornea Lapland. TIPULIDAE Psiloconopa, wings divaricated, venation nearly as is Limnobia, Mg. Zw. i. t. 5, f. 6, antennae 16-jointed, moniliform, eyes meeting under the antenna , proboscis short, palpi 4-jointed ; one species Ps. meigeni, 3 lines long, like Erioptera lateralis in colour ; found throughout the northern provinces in watery places. Tricyphona, distinguished from Limnobia by the peculiar venation, type L. immaculata, Mg. Zw. i. t. 5, f. 8. Dicranota, antenna? 13-jointed, type Limnobia pavida Hal. (D. guerinii Ztt.), and it seems to us that L. bimaculata (Schummel) is congenerous, although Zetterstedt has left that species among his Limnobiae. LEPTIDAE Ptiolina Stg., dismembered from Atherix, third joint of antenna oval, with short apical arista; A. melcena Mg. BOMBYLIDAE Psilocephala, founded on the species of Thereva with naked face ; but Loew (Beytr. ii.) has retained them as a portion of that genus. ACROCERIDAE Sphcerogaster, resembling Cyrtus in the antennae and exserted proboscis (which is horizontal and as long as the head), and Henops in venation ; the alulae very small ; one species Sph. arcticus, little more than a line long, a single specimen found on a mountain of Finmark. EMPIDAE Anthalia, like Euthyneura, third joint of antennae ovate, without a style, hind femora rather long ; seven species, almost exclusively northern; A.furcata having the cubital vein forked, should probably be removed from this genus. Iteaphila, like Euthyneura, but the cubital vein forked ; two species, chiefly northern. Hormopeza, seems to come near to Ragas, but the third joint of the antenna? is ovate, and the style longer in proportion, the fore tarsi moniliform in the male ; one species H. obliterata, above two lines long; Tornea Lapland and the north of Bothnia. Microcera Ztt. is synonymous with Sciodromia. Phyllodromia, type Tachydromia melanocephala Fabr., differing from Hemerodromia chiefly by the simple cubital vein. Wiedemannia, type Heleodromia bistigma Curtis (W. borealis Ztt.)] Wahlberg has remarked that longicornis is the only genuine Brachystoma, and that the other species referred to that genus by Zetterstedt belong to Paramesia Macquart (synonymous with Heleodromia) ; we would add that both Heleodromia and Wiedemannia, and, perhaps, Ardoptera too, might be reunited with Clinocera; and Wiedemannia has been employed as a generic name, not only in another family of Diptera, but in botany also. DOLICHOPIDAE Thinophilus, like Rhaphium, but the third joint of antennae round, with dorsal arista ; type Rhaphium flavipalpe Ztt. PLATYPEZIDAE Platycnema, two species, type Empis pulicaria Fin. Microsania, including Cyrtoma pectipennis Mg. and a second species, differs from the preceding chiefly in venation, the cubital vein running to the hind margin. PIPUNCULIDAE Nephrocerus, antennae with the third joint reniform, the venation nearly as in Pipunculus auctus; two species, larger than any of that genus. MUSCIDAE, 1. CALYPTERI Micra, placed next to Phania, the clothing pubescence without bristles, the abdomen ovate ; one species M. Trixina, 2 lines long, a single specimen found in Northland. Wahlbergia, type Tachina melanura Mg., allied to Ocyptera, the radial vein longer and not curved, the angle of the subapical vein more obtuse, the alulae smaller. Gymnopeza, distinguished from Phasia by the nearly naked body and legs, and the gentle curvature of the subapical vein, which joins the cubital exactly at the end, and resembling Phania by the incurved extremity of the abdomen ; two species, scarcely exceeding 2 lines in length. Cinochira, of rather doubtful affinity ; the subapical vein approaching the cubital with a slight curve towards the end, the alulae pretty large, antennae with the third joint not longer than the rest, rounded, the arista long and capillary, eyes distant (in male ?) ; one species C. atra, 2 lines long ; allied to the Tachinides in the opinion of Wahlberg the discoverer, but placed by Zetterstedt at the end of the Muscides, immediately before the Anthomyzides. 2. ACALYPTERI Leptopa, one species L.filiformis Ztt. (Cordylura flava Hal., Ent. Mag. A.D. 1836, but Wiedemann had previously a C. flava from Egypt); separated from Cordylura on account of the shorter antenna and oblong eyes ; the orbits of the face very prominent below, where they bear the ordinary "mystacine" cilia. Ectinocera, differing from Tetanocera in the comparative length of the joints of the antennae, the third being elongated, and the two preceding short ; E. borealis, a northern species, 2 lines long. Psceroptera Wlbg., allied to Ortalis, and the wings spotted in like manner, hypostoma short not keeled, habit of Sepsis; four species, from 1 to 3 lines in length ; frequent the trunks of trees, running with the wings extended horizontally in constant motion ; the larvae feed under the bark. Colobcea, type Opomyza bifasciella Fin. (Sciomyza concentrica Mg.). Rhynchaea, resembling Lonchaea, but the oral angles of the face armed with a bristle ; one species Rh. lonchaeoides, 1 line long. Macrochira (Clusia Hal, Ann. Nat. Hist, ii., 188, A.D. 1838), type Heteromyza flava Mg., but Zetterstedt has not recognised their identity, though he happens to have adopted the same trivial name. Amphipogon Wlbg., much resembles the preceding, but the round third joint of antenna bears the naked arista near the base ; one species A. spectrum Wlbg., between 2 and 3 lines long, the male distinguished by the cheeks, hypopygium, fore and hind thighs, and middle tibiaa being pectinated; generally found on fungi in the northern provinces. Ampycophora Wlbg., identified by Zetterstedt with Aulacigaster Macquart. Earomyia, like Lonchaea, face more prominent, eyes smaller ; one species E. lonchaeoides, 2 lines long. Anthophilina, synonymous with Leptomyza Macquart. Lobioptera Wlbg., allied to Milichia, but the fore edge of the wing with a deep incision at the end of the subcostal vein, and the costal vein vanishes before the end of the subapical ; one species L. ludens Wlbg., 1 line long. Selachops Wlbg., like Lonchcea, but the mediastinal vein indistinct, and the ovipositor not protruded, form of the head somewhat like Tetanops, the protuberant front overhanging the short antennae, the third joint of which is round, with the naked arista implanted towards the tip ; one species S. flavocincta Wlbg. (Eucodocera bicolor Lw.), occurring in the northern and central provinces, and abundant on the banks of the River Luleaa. And of the " sections" of Stenhammar, but which are formally named and divided as genera, Parydra Stnh. is synonymous with Napaea Desvoidy, but the latter name pre-occupied in botany ; Epipela Stnh. is Ilythea Hal. ; Philygria Stnh. is Hydrina Desvoidy, including Hyadina and Axysta Hal. ; Clasiopa Stnh. is Discocerina Macq., as limited by Haliday, A.D. 1839. HIPPOBOSCIDLE Leptopteryx, of rather doubtful affinity, differing from the rest of this family by the distinctly triarticulate antennas without an arista, long slender legs, and wings not distinctly veined; L. nivalis, 1J lines long; a single specimen found crawling on the mountain snow in Lapland. Among the more remarkable species made known by Zetterstedt, are a species of Scenopinus, with the second branch of the cubital vein again forked, S. furcinervis, and an Echinomyia, with 4-jointed tarsi, E. tetramera. Only one specimen had occurred of each. May they not be symmetrical monstrosities, such as are not without example ? The space will not allow us to pass in review the multitude of species first made known in these volumes, or to indicate the synonyms of some, which appear to have been described before. We hope to see this yet done, as well for the " Diptera Scandinavia?," as the " Insecta Britannica," when the concluding volume of the latter shall have appeared, since the collation of both works may lead to more satisfactory results. We have endeavoured to arrive at some estimate, of course a very problematical one, of the relative numbers of Diptera in Sweden and in the British Islands. Walker, in a preface to the second volume of " Insecta Britannica," has expressed an opinion that the numbers may be about equal; but such a conclusion seems scarcely borne out by the data, as we have collected them in the annexed table : COMPARATIVE NUMBER OF RECORDED SPECIES OF

PULICIDAE Scandinavian Zetterstedt N spp. - Total - British Curtis Guide 17 Brit -

MYCETOPHILIDAE Scandinavian Zetterstedt N spp.135 Total 235 British Curtis Guide 138

CECIDOMYZIDAE Scandinavian Zetterstedt N spp. 21 Total 33 British Curtis Guide 33

BIBIONIDAE Scandinavian Zetterstedt N spp. 10 Total 37 British Curtis Guide 34

SIMULIIDAE Scandinavian Zetterstedt N spp. 5 Total 12 British Curtis Guide 13

CHIRONOMIDAE Scandinavian Zetterstedt N spp. 107 Total 222 British Curtis Guide 154

CULICIDAE Scandinavian Zetterstedt N spp. 7 Total 20 British Curtis Guide 27

PHLEBOTOMIDAE Scandinavian Zetterstedt N spp. 1 Total 10 British Curtis Guide 9

HETEROCLITAE Scandinavian Zetterstedt N spp. 1 Total 5 British Curtis Guide 10

TIPULIDAE Scandinavian Zetterstedt N spp. 62 Total 198 British Curtis Guide 161

RHYPHIDAE Scandinavian Zetterstedt N spp. 0 Total 3 British Curtis Guide 4

STRATIOMIDAE Scandinavian Zetterstedt N spp. 9 Total 42 British Curtis Guide 50 Walker Ins Brit 49

XYLOPHAGIDAE Scandinavian Zetterstedt N spp. 0 Total 4 British Curtis Guide 2 Walker Ins Brit 3

TABANIDAE Scandinavian Zetterstedt N spp. 16 Total 38 British Curtis Guide 29 Walker Ins Brit 17

ACROCERIDAE Scandinavian Zetterstedt N spp. 2 Total 6 British Curtis Guide 4 Walker Ins Brit 3

LEPTIDAE Scandinavian Zetterstedt N spp. 3 Total 19 British Curtis Guide 20 Walker Ins Brit 15

BOMBYLIDAE Scandinavian Zetterstedt N spp. 4 Total 35 British Curtis Guide 27 Walker Ins Brit 17

SCENOPINIDAE Scandinavian Zetterstedt N spp. 1 Total 3 British Curtis Guide (8) Walker Ins Brit 2

EMPIDAE Scandinavian Zetterstedt N spp. 146 Total 267 British Curtis Guide 183 Walker Ins 155

DOLICHOPIDAE Scandinavian Zetterstedt N spp. 104 Total 204 British Curtis Guide 132 Walker Ins Brit 138

LONCHOPTERIDAE Scandinavian Zetterstedt N spp. 3 Total 8 British Curtis Guide 8 Walker Ins Brit 5

PLATYPEZIDAE Scandinavian Zetterstedt N spp. 8 Total 24 British Curtis Guide 19 Walker Ins Brit 17

PIPUNCULIDAE Scandinavian Zetterstedt N spp. 11 Total 25 British Curtis Guide 14 Walker Ins Brit 12

SYRPHIDAE Scandinavian Zetterstedt N spp. 106 Total 284 British Curtis Guide 210 Walker Ins Brit 153

CONOPIDAE Scandinavian Zetterstedt N spp. 0 Total 7 British Curtis Guide 8 Walker Ins Brit 9

MUSCIDAE Calyptrati Scandinavian Zetterstedt N spp. 473 Total 859 British Curtis Guide 369 MUSCIDAE Acalyptrati Scandinavian Zetterstedt N spp. 338 Total 775 British Curtis Guide 584

Muscidae Walker Ins Brit 730* (computed)

OESTRIDAE Scandinavian Zetterstedt N spp. 1 Total 11 British Curtis Guide 8 Walker Ins Brit 7

PHORIDAE Scandinavian Zetterstedt N spp. 16 Total 38 British Curtis Guide 32 Walker Ins Brit 18

HIPPOBOSCIDAE Scandinavian Zetterstedt N spp. 1 Total 7 British Curtis Guide 10 Walker Ins Brit 5

NYCTEREBIDAE Scandinavian Zetterstedt N spp. 0 Total 0 British Curtis Guide 2 Walker Ins Brit 2

TOTAL DIPTERA Scandinavian Zetterstedt N spp.1599 Total 3468 British Curtis Guide 2353

We may here observe that since the completion of Zetterstedt's work in 1852, more species appear to have been added to the Swedish Diptera than have been added to the British since 1851 when the first volme of Insecta Britannica was published, if we may judge from a comparison of one or two of the principal families in each. Thus the Dolichopidae have been increased by two with us and as many for Sweden: the Empidae by three for Sweden and none here. Curtis in his Guide has enumerated, as it appears, 2,335 species of British Diptera, exclusive of the Pulicidce, which neither he nor Zetterstedt has included in this order. Of these, 650 belong to the families treated in detail in the first of Walker's volumes, where they are reduced to 620, out of which 470, or more than three-fourths, are 'described in the DIPTERA SCANDINAVIAE.If the same proportion hold good in the remaining families, the total number of British species known would be about 2,130, and we might expect above 1,600 of them in Zetterstedt. Walker, however, thinks the Tachinides and Anthomyzides are much more numerous than has been supposed hitherto. Adopting his estimate of them (uncertain as such a computation of species unnamed may be), we should have nearly 400 to be added to the number of these given in the Guide, still leaving the total of British Diptera. short of the Swedish by about 950 species. Nor does this seem a very improbable excess on the other side, taking into account the extent of the peninsula, with the greater variety of temperature and elevation, the tracts that border on the Arctic circle, the Alpine chains of Lapland and Norway, the breadth of primeval forest, and the more genial summer of the south of Sweden, parted only by a narrow strait from Jutland and the vicinity of central Europe. Accordingly, the Swedish fauna has representatives of many Continental genera unknown with us Ceroplatus 6 spp., Gnoriste 3, Penthetria, Macropeza, Chionea 2, Pachystomus, Canomyia, Hexatoma, Microsania 2, Gloma, Pelecocera 2, Stachynia, Lophosia, Wahlbergia, Cystogaster, Rhinophora 2, Dialyta, Selachops, Colobaaa ; against which we can set off only Mochlonyx, Sycorax, Geranomyia, Actina, Spania, Euthyneura 2, Ulidia, Lucina, Eurhina, Camarota, Tichomyza, Nycteribia 2. So far as known at present, the following Pachyneura, Corynocera, Psiloconopa, Sphaerogaster, Anthalia, Iteaphila, Hormopeza, Nephrocerus, Gymnopeza, Ciuochira, Ectinocera, Psasroptera, Rhynchasa, Amphipogon, Earomyia, Lobioptera, Leptopteryx appear to be peculiar to the Scandinavian fauna; while the British islands claim on their side Leptomorphus, Epidapus, Cluuio, Ragas, Aphrosylus, Tethina, Atissa, Glenanthe, Canace, unknown to Sweden. In certain genera of wide geographical range, and rich in species, the great disparity between the lists is probably owing, in part, to the neglect of them by the British collectors. The genus Rhamphomyia numbers only 24 species in Curtis's Guide, reduced to 10 by Walker ; while Zetterstedt has described no less than 72, and, out of that number, 21 as new species of Swedish authors. Other genera augmented largely, in like manner, if not in equal proportion, are Anthomyia with new species 122 to 68 previously described, Alicia 176 to 66, Tachina 112 to 94,Cordylura 46 to 21, Dolichopus 71 to 65, Mycetophila 48 to 20, and many more which might be mentioned. We had extracted from the INSECTA LAPPONICA a list of species given there as proper to Lapland or the northern provinces of Sweden, which have been found in these islands. Later investigation, however, has proved most of these to be diffused farther south, several of them extending into Germany also ; and probably the few remaining exceptions may also be withdrawn by future research. It is possible that North Britain, when explored more diligently, may yield other species hitherto attributed as peculiar to the northern provinces of Scandinavia ; but it is not likely that the number should be considerable, since our mountains scarcely attain to the limits of an Alpine fauna, and the disconnected lower ranges are everywhere comparatively poor in number of species, and in peculiar forms. But experiment will best solve the question, which at present we approach with such imperfect evidence.Zetterstedt is not one of the writers who are content to make a parade of erudition, by transcribing synonyms one after another, without the pains of critical discrimination. The authorities he cites have evidently been collated with scrupulous care, while he has not thought it necessary, in general, to go back to the older authorities, with the exception of Linnaeus, Fabricius, and Degeer. But he has not had access to all the recent sources, especially those of the English literature, so that some portions of his matter will turn out to have been anticipated. The admirable BRITISH ENTOMOLOGY, of Curtis, is not once referred to, and thus, among other things, the genus Dolichopeza is attributed, without remark, to Meigen, who had omitted to cite from Curtis, the original author. Hence, also, the representatives of other modern genera, in the Swedish fauna, lie disguised under alias names Diadocidia ferruginosa as Sciara testacea Catocha under Lestremia Corynoneura among the Chironomi of Zetterstedt.Having inserted, for completeness' sake, the descriptions from otherpens of some species, the originals of which he had not an opportunity of collating, he has, consequently, been led, in one or two instances, to give the same insect twice over ; thus,, the genus Cordyla appears among the Rhyphii, and, again, as Pachypalpus (Macquart), among the Mycetophilinae, and Ditomyia annulata is twice described as Ceroplatus flavus, and as Mycetobia annulata. He has not constantly regarded the strict law of priority to which we have been accustomed to defer, in the application of generic and trivial names. Fallen and Fabricius seem to weigh more with him sometimes than age or usage,and rules are made to yield to predilection. We will let the dates stand, instead of statements in detail, for judgment of the principal instances of this sort, which affect thegeneric nomenclature. Zetterstedt has adopted (1) Hirtea Fb. (1798) for Bibio Geoffroy (1764) ; Hirtea Scopoli (1763) being a different genus. (2) Chenesia Macq. (1834) for Orphnephila Haliday(1831), or Thaumalea Ruthe (same year). (3) Sicus Fb. (1798) for Coenomyia Latr. (1797) ; Sicus of Scopoli (1763) being Myopa. (4) Eristalis Fallen (1810) for Chilosia Mg. ; whereas Eristalis was first named and characterized by Latreille in 1804, while Eristalis of Fb. Antl. (1805) is made up of species of the genera Chilosia, Eristalis, Helophilus, Merodon, Mallota, Milesia, Eumerns, Pipiza and Chrysogaster. (5) Syrphus Fallen, for Eristalis Latr.; Meigen having defined the genus Syrphus otherwise in 1803, and Syrphus of Fb. Antl. including Volucella and Sericomyia along with part of Eristalis. (6) Scaeva Fb. (1805) for Syrphus, previously applied by Meigen as above. (7) Scatomyza Fallen (1810) for Scatophaga Mg. (1803) and (8) Scatophaga Fallen for Psila Mg. (1803), being four years before Jurine applied the name of Psilus to the Hymenopterous genus Diapria Latr. (1797). (9) Oxyrhina Mg. (1838) for Trigonometopus Macq. (1835). (lO) UlidiaMg. (1826) for Mosillus Latr. (1804), or Chrysomyza Fallen (1817). But Ulidia also maybe retained, being limited, according to Loew's suggestion (Beytr. i. 27), to U. erythrophthalma and the allied species. Here we close the chapter of criticism ; and if we should seem to have discharged the task in a spirit more captious than tolerant, the volumes on which we have dwelt so long do not need, and could not gain by, any commendation we might bestow, while every correction, and every doubt, may contribute in some small degree to their better use, which we would desire to see more general in the hands of our fellow-students. We lay them down, glad to see that the latest portions of his long labours betray no symptoms of failing eyes or energy diminished, and hoping that the venerable author, now in his seventieth year, may be enabled, next, to complete a like history of the HEMIPTERA of Sweden, which we are authorized to expect from his hand. A. H. H.