586 Tlie Fossil Crab of Gay Head. 



eral form those of the Cancridae. They are almost exactly 

 similar to those of Pseudorhombila as figured by Milnc- 

 Edwards,* but are somewhat shorter. The carpus is nearly 

 quadrangular, a little uneven on the upper surface, and 

 armed with a strong tooth at the inner angle. The hands 

 are smooth and unarmed, with fingers not longer than the 

 palm, and somewhat tuberculated toward their extremities. 

 Of the ambulatory feet we have few and very imperfect indi- 

 cations. It can only be said, that they appear to be smooth, 

 without teeth or spines ; and that the thighs or meros-joints 

 are of great breadth, though not particularly compressed. 



Of the outer maxillipeds., (PI. XII., fig. 2,) I find reliable 

 specimens only of the ischium-joint of the endognath, and 

 of the first joint of the exognath. The latter is remarkable 

 for its very considerable breadth, being more than half as 

 broad as the ischium of the endognath. This ischium is a 

 little more than one half longer than broad, marked with scat- 

 tered shallow pits and with the usual longitudinal sulcus, 

 and ornamented along its inner margin with crowded and 

 minute punctures for the attachment of bristles, with which 

 this margin was in life densely clothed. Of the meros of 

 these maxillipeds I find only small and doubtful fragments, 

 which, however, seem to indicate a strong prominence of 

 the external angle of this joint, — stronger in fact than I 

 have ventured to represent in the diagram. 



The sternum (PL XII., fig. 3), is quite well preserved, ex- 

 cept as regards its posterior extremity, in several specimens, 

 which have all belonged to male individuals. It is rather 

 broadly ex))anded anteriorly, and very little convex, even in 

 a longitudinal sense. Its anterior triangular projection is 

 separated by a slight transverse sulcus, and there are, in 

 some examples, slight indications of a transverse sulcus pos- 

 terior to this, arising from the next notches of the margin, and 

 bending backward. At the posterior margin of the second 



* Arch, du Musdum, T. VII., I'l. xi. f. J. 



