CRUSTACEANS For studying this class of animals, characteristically though not exclusively aquatic, Suffolk makes kindly provision. It includes among its natural advantages a wealth of waters helpful to this purpose. Several slow-flowing rivers at various points form lake-like expansions. Little winding brooks feed the more important streams. Watercourses wide or narrow frequently intersect the land to regulate its drainage. Ponds and wells and marshes are not wanting. In all directions aquatic plants are present to feed, to shelter, or sometimes to entrap innumerable crustacean tenants. A considerable sea-board allows the species of the North Sea to approach the eastern border of the county. Fleets of trawlers bring to its harbours a vast variety of fishes, on which a due proportion of parasitic Entomostraca are always sure to be lurking. Nevertheless, in the past the carcinology of Suffolk, in regard to several orders and tribes, has been much neglected. To this neglect the creatures themselves contribute by their prevailing love of concealment. In the fishing industry the hard necessities of business leave men little time for paying attention to the intrusive fish-lice and sea-fleas, which are practically their competitors in the same trade. For the more or less popular pursuit of shore-hunting, the coast-line of Suffolk is not wholly satisfactory. Much of it is too exposed and unindented to favour the immediate approach of shelter-loving animals. At Yarmouth the ebb and flow from the north coinciding with the flow and ebb from the south by their counter- action give to the rise and fall of the tide a very restricted range. Hence any one whose field of exploration is between tide-marks finds there but little encouragement. The earliest notices of Crustacea observed in this county seem to be those which occur in the earliest writings of Dr. William Elford Leach, who, while quite a young man, nearly a hundred years ago won distinction for himself and for English science by his scientific treatment of this class. As will be shown in due course, he mentions from this coast four species of Malacostraca. Then followed an interval of some fifty years, during which apparently no further records were forth- coming, until a new epoch opened with Dr. G. S. Brady's important monograph on Recent British Ostracoda, published by the Linnean Society in 1868. It is rather surprising that this work did not more largely stimulate the collection of entomostracans in a district so admirably fitted to supply them in variety and abundance. It may perhaps have revealed only too clearly that to facility of col- lecting succeeds no little difficulty of discriminating these minute objects. Except for renewed researches by Dr. Brady himself, in company with his friend, the late David Robertson of Cumbrae, little effort was made to bring the micro-fauna of Suffolk into greater prominence. In 1875 the report of Dr. Aug. Metzger, on the invertebrates dredged by the German vessel Pommerania in the North Sea, added several malacostracans to the hitherto scanty list accredited to this county. Soon afterwards Dr. Brady, in his Monograph of the Copepoda of Great Britain, published by the Ray Society, recorded a few species of that order from Suffolk localities. Although the Malacostraca that have to be named are comparatively few, the species are distributed over many genera, families, and orders. They are pretty equally divided between the Podophthalma or stalk-eyed section, which have pedunculate movable eyes, and the sessile-eyed Edriophthalma, in which the eyes are fixed, without stalk or articulation. To the former section belong the crab, the lobster, the crayfish, the prawn, and the shrimp, within which alliance the popular idea of this class is often strictly confined. In the other section are included the woodlouse and the sandhopper, with many other forms in endless variety, united by the firmest bonds of relationship to the shrimp and the crab. Mankind are fastidious and, as a rule, eat only those crustaceans that can waggle their eyes, whereas almost all marine animals and many birds feed on sessile-eyed • species without reluctance. Among the Podophthalma the highest place is generally conceded to the Brachyura or short-tails, because in their organization the ganglionic chain is most concentrated, and because the actions of many among them are, 01 seem to be, in no small degree intelligent and purposeful. Between a naked savage and the well-dressed gentleman of to-day an intermediate state of civilization is represented by the Indian in his feathers and war-paint. The tribe of the Oxyrrhyncha, or crabs with sharpened beaks, behave much like the Indian. They do not indeed try to make themselves terrible in aspect, but by I 153 20
