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 



