CHYDORUS. 
277 
rapid motion of their lower antennae and legs. Their food 
consists of both animal and vegetable matter. 
Gen. 148. EURYCERCUS, Baird* 
Subquadrangular. Abdomen very broad, formed like a 
flat plate, densely serrated. Beak blunt, slightly curved 
downwards. 
Eurycercus lamellatus, Muller, sp. (Plate XVI. 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 sph^sricus, Muller, 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. 
* E vpvs, wide, and Kepicos , a tail. 
