CHYDORUS. 277 



rapid motion of their lower antennse and legs. Their food 

 consists of both animal and vegetable matter. 



Gen. 148. EUBYCERCUS, BaM* 



Subquadrangular. Abdomen very broad, formed like a 

 flat plate, densely serrated. Beak blunt, slightly curved 

 downwards. 



Eurycercus lamellatus, Miiller, sp. (Plate XYI. fig. 4.) 

 — Largest of the family; carapace olive-coloured, ciliated 

 on the front margin. 



Hab. Ponds and ditches in summer. 



Gen. 149. CHYDORUS, Leach. 



Nearly spherical. Beak very long, sharp, curved down- 

 wards. Lower antennae very short. 



Chydorus spilericus, Miiller, sp. — Shell round, smooth, 

 olive-green. 



Hab. Ponds and ditches during all the year. 



Pritchard says that the young of this species play near 

 the parent and swim towards her for protection ; she en- 

 closes them within her shell. 



* Evpus, wide, and Kepnos, a tail. 



