48 SMITHSONIAN MISCELLANEOUS COLLECTIONS 



Genus EUXANTHUS Dana 



66. EUXANTHUS MELISSA' (Herbst) Stimpson 



Plate VI, Fig. 2 



Cancer niclissa Herbst, Naturg. der Krabben und Krebse, in, 7, pi. li,. 



fig. I. 

 Atcrgatis niclissa White, Cat. Brit. Mns., 1847, p. 14. 

 Euxanthus niclissa Stimpson, Proc. Acad. Nat. Sci. Phila., x, p. ;i^ [31]. 



1858. 



The only specimen of this species found by us is a male, the 

 dimensions of which are: Length of carapax. 1.61 ; breadth, 2.54 

 inches. It was taken at Caspar Island, in the straits of the same 

 name, by Air. L. M. Squires, of the steamer "John Hancock." 



Euxanthus nitidus of Dana (loc. cit.. i, 174, pi. viii, fig. q) is not 

 improbably the young of this species. The characters in which the 

 female specimen upon which that species was founded differs from 

 the type are only those which might well be the result of differences 

 of age or sex. 



Genus POLYCREMXUvS Gerstrecker 



This genus was recently established by Gerst?ecker ( Archiv fur 

 Naturgeschichte. xxii, 120) for the reception of the Cancer ocJitodcs 

 of Herbst, a species which was referred to Panopens by Milne 

 Edwards and to Galenc by Adams and White. Its generic distinct- 

 ness is, however, sufficiently apparent, and we had named and de- 

 scribed it in our notes before seeing the paper in the Archiv. The 

 description then drawn up may without disadvantage be presented 

 here, as it details some characters not mentioned by Gerstzecker. 



Carapax subhexagonal, the lateral angles truncated and bidentate, 

 the teeth being equal. Front rather narrow, considerably produced, 

 emarginate at the middle. Antennae with the basal article joined to 

 a process from the frontal margin, as in Xantlio, the movable portion 

 placed in the hiatus of the orbit. Antennulae oblique. Orbit with 

 three closed fissures at the exterior margin, two above and one just 

 beneath the external angle. The orbits are directed obliquely up- 

 ward and not forward, so that the whole inferior margin, as well 

 as the sharp inner angle, may be seen from above when the eyes 

 are retracted. Epistome of considerable length ; as long as in most 

 Parthenopidcc- Meros of hectognathopoda broader than long, trun- 



^ EuxautJiopsis cxsculf>ta (Herbst). 



