CYAMID.E. 



affixed upon a common, elongated basal piece, inserted 

 betwen the basal joints of the first pair, and the mouth 

 is closed below by a transverse piece (fig. g), emarginate 

 in its fore margin, which Savigny terms a " levre auxiliare 

 sans lobes," but which we regard as the ventral surface of 

 the segment that carries the pair of foot jaws (which are 

 attached at its sides); these are five-jointed, the fourth 

 being the largest. 



The first segment of the bodv is small, with the front 



O / 



part rounded on its upper edge, its lower being dilated 

 in the middle into an angle. 



The second segment is much longer than either of 

 the two following, its fore margin is nearly straight, 

 having a very minute rounded prominence towards each 

 of its lateral anterior angles ; it is deeply channeled 

 across its centre. The legs attached to this segment are 

 very large and broad, the second joint strongly angulated 

 on its upper edge, the small third joint rounded and 

 prominent on its lower edge, and the fourth joint with a 

 moderate semi-lunate impression on its lower edge. The 

 third and fourth segments of the body are very short, 

 the fourth having its sides produced at the posterior 

 lateral angles, whilst its hinder margin is emarginate on 

 each side. The fifth, sixth, and seventh segments are 

 each as long as the second, but gradually narrowed, their 

 fore and hind margins are sinuated, leaving spaces be- 

 tween the joints. The legs attached to these three seg- 

 ments are nearly uniform in size, large and broad, with 

 the fourth joint somewhat conical, having the upper edge 

 rounded ; the terminal joint in all the legs is very acute, 

 curved, and as long as the preceding joint, thus giving 

 the animal strong powers of prehension. The tail is 

 very minute and rudimental. The full-grown female 

 has the body wider than the male, and has the third and 



