l86 SMITHSONIAN MISCELLANEOUS COLLECTIONS 



nent tooth on the crest near the middle, and is armed with a tooth 

 within near the base ; the immovable finger bears a strong tooth at 

 the middle of its inner edge. Ambulatory feet long, slender, 

 slightly compressed ; meros not dilated ; dactyli as long as the penult 

 joint, and slightly sulcated on one side toward extremities; dactylus 

 of last pair of feet shorter than the others. Color white or pale 

 yellowish-brown, obscured by sordes. Length of carapax in the 

 female, 0.3; breadth, 0.39; length of hand, 0.5. 



Taken abundantly with the trawl on a mudd}^ bottom in six fath- 

 oms, in a bay on the coast of China opposite Hongkong. 



Genus PACHYCHELES Stimpson 



This genus is readily recognized by its peculiar habit. Its form 

 is less depressed than in Petrolistlies, and, while the carapax is 

 smooth, the chelipeds are thick and coarse in appearance, short, and 

 irregularly protuberant or granulated above. The carapax is 

 rounded-ovate, at least as broad as long, with the lateral margins 

 marked by an elevated line, the front somewhat deflexed, a little 

 prominent at the middle, and subacute, but never dentated, with its 

 apex concealed by pubescence. The epimeral pieces of the carapax 

 are not soldered, but separated by membranaceous interspaces, the 

 posterior square piece being particularly well defined. In this latter 

 point this genus differs from all the others of the family. The first 

 joint of the external antennae is sufficiently well developed in its 

 internal angle, touching, though not joining, the superior margin of 

 the carapax, and excluding the movable portion from the orbit ; it is, 

 however, not produced outward or backward, as in PorceUana 

 proper and allied genera. The carpus of the chelipeds is remarkabh' 

 short and broad. Dactyli of the ambulatory feet normal in form. 



The genus is littoral in its habits, and is an inhabitant of the tem- 

 perate and warm-temperate zones in the Pacific and Indian Oceans. 



PorceUana grossimana of Guerin may be considered the type of 

 this genus, which also includes the P. iiwiiilifcra of Dana and P. 

 natalensis Krauss. 



293. PACHYCHELES PECTINICARPUS Stimpson 

 Plate XXIII, Fig. 5 



Pachycheles pectinicarpus Stimpson, Proc. Acad. Nat. Sci. Phila., x, p. 

 242 [80], 1858. 



Carapax broad, somewhat depressed in the middle, smooth and 

 glabrous, but obsoletely striated toward the sides. Sinus of the 

 posterior margin verv shallow. Protogastric lobules sufficientlv 



