278 HISTORY OF BRITISH CRUSTACEA. 



Chydorus globosus, Baird. — Shell quite globular, six 

 times larger than in C. sjj/itsricus, spotted with black. 

 Hab. Ponds in the vicinity of London. 



Gen. 150. CAMPTOCEECUS, Baird* 



Oval; abdomen very long, slender, and very flexible, 

 much serrated. Beak blunt, slightly curved downwards. 



Camptocercus macrourus, Miiller, sp. — Shell pellucid, 

 whitish ; abdomen very long and slender. The animal, Dr. 

 Baird tells us, can twist its abdomen completely round in a 

 circle, and then, unbending it, thrust it far out beyond the 

 shell. 



Hab. Highgate ponds, and other places near London. 



Gen. 151. ACROPEEUS, Baird. 



Shell rounded behind, somewhat harp-shaped, terminating 

 in an obtuse point projecting forwards. Lower antennae long. 

 Beak blunt, curved downwards. 



Acroperus harp^e, Baird. — Shell strongly ribbed, some- 

 what obliquely, giving the shell some resemblance to a harp. 



* Ka/xTTTos, flexible, and Kepnos, a tail. 



