230 fiRAMMAR OF ENTOMOLOGY. 



short clavated antennae ; mandibles short and 

 obtuse, but strong ; maxillae somewhat obtuse ; 

 galea palpiform, exarticulate ; fore legs long, 

 middle and hind legs short and incrassated ; car- 

 nivorous. Inhabits water, performing in the sun- 

 shine its beautiful and social gyrations on the 

 surface. Gyrinus. 



766. Carnivorous water-beetles (Dytisciles). 

 Larva with strong arcuate mandibles, perforated 

 at the extremity for suction; carnivorous, aquatic, 

 natatory. Pupa changes in the earth, at the 

 margins of ponds, among roots of trees and 

 grass. Imago with filiform antennae ; man- 

 dibles short and strong ; maxillae arcuate and 

 very acute ; galea palpiform and articulate ; the 

 fore tarsi patellated in the males ; the middle and 

 hind legs flattened and ciliated ; form oval. Inhabits 

 water, feeding on aquatic animals ; swims with 

 great ease and swiftness, moving the corresponding 

 legs simultaneously. Acilius, Dytisciis, Colym- 

 betes, Noierus, Hydroporus. 



767. Ground-beetles {Carahites). Larva with 

 strong arcuate mandibles ; active and carnivorous. 

 Inhabits roots of grass, rubbish-heaps, decaying 

 vegetables, moss, under stones, &c. in which 

 situations it pursues and seizes its prey. Pupa 

 changes in the earth. Imago with moniliform 

 antennse ; mandibles moderately short, very strong ; 

 maxillae terminate in a blade, sometimes acute, but 

 never articulated; galea articulate and palpiform. 



