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 
LONG-BEAKED SPIDER-CRAB (nat. 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 Leucosiidce 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 Dorippe, 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 (nat. size). 
