68 



A COBNISH EAIJNA. 



the form of its carapace, which, is Lyre-shaped, and is as long as 

 it is broad. 



Mr. Bell considers it to be a distinct Gremis from Platyonychus, 

 but I doubt if lie has made out more than a specific separation, 

 even if he has good evidence of that. 

 Poetumnus latipes. — Wide Foot. — Pennant. 



Platyonychus latipes — Edwards, Hist, des Crust., t l,p. 436; 

 Couch's Cornish Fanna, p. 71. 



Portumnus variegatus — Leach, Bell, Hist. Stalk-Eyed Crust., 

 p. 85. 



It is found at low water mark on sandy beaches, in many 

 places, where it burrows. Though not common it is tolerably 

 abundant where taken. 



Genus, Polybitjs. — Leach. 

 Carapace nearly circular, much depressed, anterior margin 

 dentated, posterior pair of legs having the terminal joint flattened 

 for swimming. 



Polybitjs henslowii. — Nipper or Henslow's Swimming Crab. — 

 Leach, Malac. Brit., t. 1, 9; Milne Edwards, Hist, des Crust., 

 t. I, p. 439. 



" This, more than any of the others, is a swimming crab ; for 

 whilst the other British species of this family are only able to 

 shoot themselves along from one low prominence to another, the 

 nipper crab, as our fishermen term it, mounts to the surface 

 over the deepest water, in pursuit of its prey, among which are 

 numbered the most active fishes, as the Mackerel and Pauning 

 Pollock, the skin of which it pierces with its sharp pincers, keep- 

 ing its hold until the terrified victim becomes exhausted. We 

 are witnesses to this curious method of obtaining food in the 

 summer only, at which season the fishermen's nets intercept them 

 and their prey together; and it is probable that, in colder 

 weather, they keep at the bottom in deep water, from which, 

 however, I have never seen them brought in the stomachs of 

 fishes, so far as my observation extends. It is only or chiefly the 

 male that pursues this actively predaceous existence ; but that 

 for a time they also remain quietly at the bottom, appears from 

 the fact that while, for the most part, the smooth and flattened 

 carapace is clean, I have occasionally seen it covered with small 

 corallines. ( Sertularia) . ' ' 



