A HISTORY OF SUFFOLK Huxley's statement. That celebrated writer says, 'In Crangon none of the maxillipedes bear gills,' but in the very next paragraph adds, 'I can find only one arthrobranchia on the ninth somite.' This ninth somite is that which carries the third maxillipeds. The respiratory arrangements of the Podophthalma admit the theoretical possibility of four pairs of branchiae to each of the three pairs of maxillipeds and the five succeeding pairs of limbs. These breathing-organs are distinguished as podobranchiae when attached to the first joint of the appendage, as front and hind arthrobranchiae when on the connecting membrane between the limb and side-plate, and as pleurobranchiae when attached to the side-plate itself. The full number is never found, and, owing to the crowding to- gether and easily detachable nature of these organs, they are often miscounted by the careless or unwary. There are sometimes extraordinary differences between forms in many respects nearly related. Thus Panda/us montagui agrees with P. brevirostris in having five pairs of pleurobranchiae and one pair of podobranchiae ; but it has six pairs of arthrobranchiae, of which the latter species has on ly two, 10 In the Hippolytidae it is now acknowledged that Virbius fasciger is synonymous with Hippclyte variam. Leach. It was only distinguishable from it, as Metzger observes," by the transverse dorsal tufts of plumose setae, which readily fall off. These more probably mark some stage of the in- dividual life than any specific or even varietal difference. Hippolyte pusiola, Krfiyer, has now been transferred to the very extensive genus Spirontocaris, Bate, in which the mandibles have a palp, and the second pair of legs have the wrist seven-jointed, whereas in Hippolyte this wrist is three-jointed and the mandibles are without palp. In regard to the type species of Leach's genus Pandalus it is interesting to compare that author's own statements. In the article * Crustaceology ' of the Edinburgh Encyclopaedia, after defining the genus, he writes : — ' Sp. i Montagui. Rostrum turning upwards, with many teeth above, and the apex emarginate, with six teeth beneath ; antennae ringed with white and red alternately. Pandalus Montagui, Leach, Malacos. Brit. Pandalus, Tab. A, named in honour of its first discoverer, Montagu, by whom it was called Jstacus maculatus. The Rev. J. Fleming took this species in Zetland, whose successful labours in that country speak more than we can do in words.' " But in the Malacostraca Podophthalmata Britanniae^^ Leach gives the name as Pandalus annulicornis, and writes: — 'This highly interesting species was discovered in Zetland, and in St. Andrew's Bay, Scotland, by the Rev. Dr. Fleming, who most kindly gave me the specimens I originally described in the Edinburgh Encyclopaedia. It was observed also by Montagu, who found it on the coast of Devon ; and by Mrs. D. Turner it was noticed at Yarmouth, and pointed out to Mr. J. D. C. Sowerby as distinct from the common prawn. It is used at Yarmouth as an article of food, and is at that place so much esteemed for the" table as to afford constant employment during the summer season to several fishermen, who take it in abundance at a considerable distance from the shore, and name it from that circumstance the sea-shrimp.' By the common prawn is no doubt intended Leander serratus (Pennant), an early record of which in Suffolk may therefore be credited to the acute observation of Mrs. Dawson Turner. Why Leach discarded the name maculatus given by Montagu, and the name montagui given by himself, to the first species of Pandalus, must be left to conjecture. Possibly maculatus was thought inappro- priate, and annulicornis especially appropriate, but according to modern ideas the name montagui found with the earliest description of the species must prevail. Leach described the first pair of feet as adactylus or fingerless, meaning that they had a simple stiliform ending. In 1899 Dr. Caiman pointed out that they are in fact microscopically chelate, and at the same time instituted a new genus Pandalina for Rathke's P. brevirostris. This is distinguished from the preceding species by a much shorter rostrum, by a much less subdivided wrist of the second legs, as well as by the branchial formula above described. When the British Association met at Ipswich in 1895, during an excur- sion, Pandalus montagui was taken abundantly in the River Stour. What diminution in the salinity of the water this ' sea-shrimp ' can put up with does not appear to have been ascertained. Palaemonetes varians (Leach) makes itself at home in water that is quite fresh, as well as in the sea. It was originally placed in the genus Palaemon by Leach, who speaks of it as ' common at Yar- mouth,' " and ' very common on the Devonshire, Glamorgan, and Norfolk coasts, where it is taken as an article of food.' ^^ It is distinguished, by having no palp to the mandibles, from Palaemon and Leander, in which there is a three-jointed mandibular palp. The Schizopoda, called cleft-footed because the legs have two branches, are here represented according to Metzger by Mysis inermis (Rathke) and Gastrosaccus sanctus, van Beneden, both taken at 16 fathoms depth south-east of Yarmouth.'^ The family Mysidae, to which these belong, is remarkable as having no proper branchiae. M. inermis is often referred to White's g&nvis Macromysis, '" Caiman, Jnn. Nat. Hist. (1899), Ser. 7, iii, 30, 37. " Nordseefahrt Pomm. 305. " Op. cit. (1814), vii, 432. " Op. cit. (i Mar. 1815), text to pi. xl. " Edinb. Encycl. vii. 4.32. " Malac. Pod. Brit, (i May 1816), text to pi. xliii, figs. 14-16. " Nordseefahrl Pomm. 288, 289. 156
