2/0 CRUSTACEA, ECHINODERMS, ETC. 



curved thorns. Inachus Dorsettensis, Achceus cranchii, 

 and Stenorynchus phalangium are still better entitled 

 to the name of " spider " crabs, on account of their 

 small bodies and extremely long legs. 



Fig. 201. 



The Spider Crab (Hyas araneus). 



In addition to the above, the interesting group of 

 "swimming crabs" has been introduced into the Crystal 

 Palace and other aquaria, where at least half-a-dozen 

 species are to be seen. The principal general are 

 Polybius, Portunus, and Portumnus. Their adaptation 

 to swimming habits is at once evident on seeing their 

 flattened, oar-like hind legs. When swimming they 

 usually take to the mid-water. The "masked crab" 

 is to be found in some of our public acquaria, and is 

 undoubtedly one of the most attractive. The male and 

 female differ so much in general appearance that they 



