Sub-Glass 2. Malacostraca. Order 6. Decapoda. 



227 



tail doubles up, and the Crab is henceforth a creeping animal. The Shore Crab 

 {Careinas mcenas) occurs in great numbers on the coasts of England and other 

 parts of Europe. Like other Grabs it is an active, crafty, predaceous animal, 

 which makes strenuous resistance when attacked. The large and broad, thick- 

 sheUed form. Black-clawed Crab or Punger {Cancer pagurus), also 

 lives on English coasts in deeper water. 



Order 7. Stomatopoda. 



The Stomatopoda are Malacostraca witli large stalked eyes, 

 with a carapace, and with a powerful abdomen. The 

 carapace is, however, relatively small, and the four posterior thoracic 

 segments are free, movable, strongly built, and not covered by it. 

 The abdomen is strong, almost straight, with the usual six pairs of 

 appendages, of which the hindmost forms the tail fin, together with 

 the seventh segment, whilst those of the other five pairs are all strong, 



Fig. 189. Squilla. VIII eighth thoracic segment ; 1, 7 first and seventh abdominal 

 segments; A^, A^ antennae; g gill; Hj, Hj first and sixth abdominal appendages; 

 K^, Kg second and eighth thoracic appendages ; o eye ; S carapace. — After Liitken. 



swimming feet, coupled together, and bearing on their outer rami, 

 large, branching gills. Of the eight pairs of thoracic limbs, the 

 first five are all prehensile ; the last joint can be folded back upon 

 the penultimate. The second pair is specially well developed. The 

 last three pairs of thoracic appendages are feeble walking legs. The 

 Stomatopoda do not carry their eggs about. The young animal passes 

 through a metamorphosis, the first stages of which are not 

 accurately known. The more advanced larvse are delicate and 

 transparent, but otherwise very like the adult ; they are characteristic 

 members of the pelagic fauna. 



The group, which includes relatively few and fairly uniform 

 members, belongs to warm seas. A noteworthy species, Squilla 

 mantis, is found on English coasts. 



Class 2. Myriapoda (Centipedes). 



The multiarticulate, usually elongate body, is covered with a 

 chitinous skin, which may, or may not, be calcified. The head is 

 clearly defined, aud is provided on either side with a group of 

 ocelli, more rarely with true lateral compound eyes; it bears also 



Q 2 



