ox THE YOUNG OF THE ROBBER CRAB. 587 



The abdomen consists of six segments, of which the last no doubt represents the 

 fused sixth segment and telson, as in Eupagurus, etc. (23, 27, 28). The segments are 



Fig. 2. 

 Second antenna. 



unarmed, save that the fifth bears a pair of stout teeth, one on each side, at the 

 hinder end. The telson (Fig. 8) has the usual fan shape with a shallow median notch as 

 in Eupagurus. On each side of the notch are five long bristles, equal in length and 



Fig. 3. 

 Right mandible, seen under the microscope as a transparent object. 



all moveably articulated. These bristles, like many of those on the limbs, bear a 

 thick fringe of very fine hairs. At the outer angle on each side is a stout immoveable 

 tooth. This arrangement, which closely resembles that figui-ed by MuUer (25) for an 

 unnamed species of Hermit Crab, differs from that in Eupagurus in having the bristles 

 of equal length and all moveably articulated, and from Spiropagurus in the median notch 



Fig. 4. 

 First maxilla. 



and the equality of the bristles. The embryonic skin fits the whole structure like a 



glove, having processes corresponding to the teeth and bristles, but no supernumerary 



w. V. 78 



