CRABS. 



261 



live a sluggish life on the floor of the sea, have the sides of the carapace produced 

 into shelf-like plates covering the legs, and the upper edges of the pincers supplied 

 with large crests. The latter shut in the cephalothorax in front, so that when at 



LOXU-BEAKED SPIDER-CRAB (liat. size). 



rest the whole animal is enclosed in a casing of shell, and resembles a smooth 

 pebble on the sea bottom. Some of the species of the family Leucosiidai are 

 remarkable for the porcelain - like appearance and texture of the carapace, 

 while in others, as in Ebalia, this plate is granular and corroded. Three or four 

 species of the latter genus occur in British waters, but the majority of the 

 Oxystomata are inhabitants of the tropics. In the genus Dorij>pe, belonging to 

 the family Dorippidce, the last two pairs of legs are short and raised on the upper 

 surface of the body behind the carapace. In 

 this position and structure they are adapted 

 for carrying foreign bodies to serve as a 

 protection. 



The aberrant forms constituting the 

 tribe Anomala differ from the other members 

 of the suborder in having sometimes as 

 many as fourteen pairs of gills, and also in 

 that the apertures of the oviducts are situated 

 upon the basis of the third pair of legs and dromia crab oat size). 



