CRUSTACEANS 245 



Resembling the Prawns in appearance are the 

 so-called " Schizopods," a name including two rather 

 dissimilar groups. Of these, the Euphausiacea (Fig. 118, 

 p. 179), are almost entirely pelagic, the other (Mysidacea) 

 are for the most part bottom-haunting forms, rarely 

 more than an inch in length. 



Of the larger Crustacea the most unfamiliar are 

 probably the squills, or mantis shrimps (Squilla) 

 (Fig. 119, p. 179), with small bodies and broad, flattened 

 tails. They carry a powerful pair of claws, which they 

 lift in a manner that recalls the mantis insect. They 

 are rarely found except in the warmer seas. 



The most highly organized, and the largest, of the 

 Crustacea, the Decapoda, are usually divided into three 

 groups : (1) The Macrura (or long-tailed), including the 

 lobsters, prawns, and shrimps (Fig. 183) ; (2) the 

 Anomura (or irregular-tailed) — these comprise, among 

 others, the hermits (Paguridae), with soft bodies 

 (Fig. 181), and the Galatheids, in which the tail is 

 broad and flattened, and can either be turned up 

 under the body or else straightened out and used 

 for swimming (Fig. 182) ; (3) the Brachyura, or 

 crabs proper — these include an immense number of 

 very different forms ; they retain, however, a sufficient 

 family resemblance for recognition as crabs. Some of 

 the more conspicuous types are the swimming crabs, in 

 which the last pair of legs are paddle-shaped and the 

 body flattened, as in the British genera Portunus and 

 Bathynectes ; and the spider crabs, which have the 

 legs long and slender, and apparently more designed 

 for concealment than locomotion, the movements of 

 these crabs being deliberate and sluggish, and their 

 bodies often furnished with a crop of seaweeds, 

 Hydroids, or sponges. The Ebalias, with their small 

 round bodies and closely tucked-in claws, might easily 



