MUSEUM OF COMPARATIVE ZOOLOGY. 1")1 



In a young female specimen, probably of this species, w liieli was dredged 

 in forty-nine fathoms, and is less than two tenths of ;in 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 posterior tooth of the antero-lateral margin is obsolete.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 tin- pits are already present on the meros of the chelipeds, 

 but tlic 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 in r, fathoms. 



Off Elbow Reef, March 21, i860. Cast No. :;. 49 fathoms. 



Subfamily EUCRATOPSINAE. 



In this group the vergal canals arc closed, ami the last joint of the 

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

 cinae ; hut the first joint oT the abdomen is well developed, ami is much 

 broader thin the second, reaching to the coxa; of the posterior feet, which 

 the second joint docs 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) dithers little from Panop< us. 



Panoplax now gen. 



This genus resembles Panopt us 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: eye- short; orbit rather small, with a slight hiatus beneath the 

 outer angle. Antenna' and outer maxillipeds as in Pa opt is. Ambula- 

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



It is very closely allied to Etta tlopsis Smith ( Enrralt Dana), but differs 

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

 bands, etc. 



Panoplax depressa nov. sp. 



Carapax faintly arcolatcd, 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 



