MUSEUM OF COMPARATIVE ZOOLOGY. 151 



In a young female specimen, probably of tbis species, which was dredged 

 in forty-nine fathoms, and is less than two tenths of an inch in length, the 

 posterior tooth of the antero-lateral margin is obsolete. The same thing 

 occurs in a young male of about the same size from St. Thomas. In this 

 young male the pits are already present on the meros of the chelipeds, 

 but the shape of the carapax is like that of the female, and the internal sub- 

 orbital lobe is much less developed than in the adult. 



Key West, 2 to 5 fathoms. 



Off Elbow Beef, March 21, 1869. Cast No. 3. 49 fathoms. 



Subfamily EUCBATOPSINAE. 



In this group the vergal canals are closed, and the last joint of the 

 sternum in the male is exposed at the anterior corners, as in the Eurypla- 

 cinae ; but the first joint of the abdomen is well developed, and is much 

 broader than the second, reaching to the coxa? of the posterior feet, which 

 the second joint does not. The third joint of the abdomen is much wider 

 than the second, but falls considerably short of the margins of the sternum: 

 The third, fourth, and fifth joints are soldered together. Except in the 

 passage of the verges through the sternum, the typical genus of this group 

 (Eucratopsis) differs little from Panopeus. 



Panoplax nov. gen. 



This genus resembles Panopeus in general appearance. The carapax is 

 somewhat depressed, and much broader than long. Antero-lateral margin 

 short, with three teeth (not including the angle of the orbit, which is not 

 prominent), and a slight emargination indicating the fifth, or posterior 

 tooth, which, being placed within as well as behind the prominent fourth 

 tooth, belongs more properly to the postero-lateral margin. Facial region 

 narrow ; eyes short ; orbit rather small, with a slight hiatus beneath the 

 outer angle. Antennas and outer maxillipeds as in Panopeus. Ambula- 

 tory feet compressed ; dactyli but little longer than the penult joint. 



It is very closely allied to Eucratopsis Smith (Eucrate Dana), but differs 

 in its broader and more depressed carapax, deflexed front, more elongated 

 hands, etc. 



Panoplax depressa nov. sp. 

 Carapax faintly areolated, and smooth and naked above. Third and 

 fourth antero-lateral teeth triangular, acute, and about equal in size, the 

 third, however, being somewhat broader. Second antero-lateral tooth half 

 as large as the third. Front deflexed, in a curve ; lobes broadly convex, 

 smooth. There is a slight, straight, acute transverse ridge crossing the 

 frontal region just above the margin. Chelipeds rather large ; carpus 



