STALK-EYED CRUSTACEA 383 



II. Abdomen not spirally twisted, composed of distinct 

 movable segments which are usually calcified {Cancellince, 

 Dana) : — 



12. Xylopagurus. 



Xylopagurus . A. Milne Edwards, A. Milne Edwards 

 and Bouvier. 



Carapace narrow, bounded by parallel edges ; it 

 terminates in front in a small rostral point. The 

 ophthalmic ring is represented by two small scales some 

 distance apart. E)e - peduncles are short and stout; 

 tiie antennae are short and thin ; the antennules are large 

 and shortened. The pincers are of unequal size and 

 unlike in shape ; the fingers move in a horizontal plane ; 

 the right is the largest and has sharp fingers ; the next 

 two pairs of legs are thin and long ; the fourth pair is 

 subchelate ; the fifth chelate. 



The abdomen terminates in a special armature in the 

 form of a plate on the penultimate ring, which is much 

 developed, widely oval, and strongly calcified. The lateral 

 appendages are inserted below and are symmetrical ; they 

 are folded in a hollow depression on the under side of the 

 joint that carries them. 



On each of the two first segments the male has, on the 

 ventral side, a pair of sexual feet. The female has on the 

 left side three unequally biramous appendages, but not 

 in pairs. 



They live in holes in wood, the holes being open 

 at both ends ; they can close the posterior door by 

 the oval plate on their abdomen, and the front door 

 by their hand. 



Range. — West Indian Sea; in deep water. 



