CRUSTACEANS In the same year the honorary secretary of the society, discussing ' Animal Life in the Leicester Corporation Water Supply,' mentions Dapbnia and Cyclops as probably accidental escapes through the filter beds. 6 The Four- teenth Report of the Museum Committee to the Town Council as to the Leicester Corporation Museum and Art Gallery, from i April, 1902, to 31 March, 1904, under the heading, 'Crustacea (trilobites, crabs, lobsters, prawns, &c.),' observes that specimens of recent freshwater forms are desiderata, and many of these might very easily be obtained by local enthusiasts in this direction from the rivers and streams of the county, our knowledge of their distribution throughout Britain generally being at present very limited, and still more so in the case of local forms. 7 It is no doubt extremely desirable that a local museum should have suitably preserved specimens of all the local fauna. There is, however, little reason to expect that the crustaceans of Leicestershire will ever excite the wonder or admiration of the multitude by an exhibition of them in show- cases. The majority of them are microscopic in size, and among the larger forms the marvels of structure and elegancies of apparel are for the most part still microscopic. The aquatic species need to be kept in liquid or imbedded in some preservative material. Consequently the ordinary passing observer requires enlarged models or very much magnified pictures of the animal and its dissected parts, if he is to appreciate these forms of life at all at their true value. For the highest sub-class of crustaceans, the Ma/acostraca, Leicestershire is singularly barren of records. All the greater is the satisfaction now to be derived from publishing the fact that Potamobius pallipes (Lereboullet), the common river crayfish, exists here as it does in so many other counties of England. It is in our strictly inland shires the solitary representative of the Macrura^ a lobster-like form, stalk-eyed, ten-legged, breathing by divided gills which are concealed under the large cephalothoracic shield or carapace. For the opportunity of making this record I am indirectly indebted to Mr. H. H. Arnold-Bemrose, J.P., F.G.S., who ascertained that at Derby members of the electric lighting staff were accustomed to catch crayfish from the canal for domestic consumption. He suggested that the same thing might happen at Leicester. In accordance with this anticipation Mr. Alfred Coulson, M.Inst.C.E., manager of the Corporation of Leicester Gas and Electric Lighting Department, obligingly writes to me under date 1 5 De- cember, 1906, ' that crayfish are caught in the canal adjoining one of their works.' Dr. W. T. Caiman, D.Sc., has also since informed me that Leicester is one of the localities from which the British Museum has received speci- mens of this crustacean. Still unrecorded, but beyond all doubt present, is the ubiquitous Gam- marus pulex (Linn.). This is a characteristic representative of the Amphipoda^ which are sessile-eyed Ma/acostraca, with fourteen legs, simple exposed gills, and a cephalothoracic shield much shorter than that of the crayfish. The species in question is one of the few that we have in fresh water. Their salt- water kindred are exuberantly diversified both round our own shores and in other parts of the globe. Just as surely as the brooks and ponds of the county 6 Tram. Leic. Lit. and Phil. Sue. v, 377. ' Op. cit. 12 (1904). i 97 13
