CRUSTACEA NORTH PACIFIC EXPLORING EXPEDITION 189 



carpus denticulated ; hand broad and flat, not twisted, with a rather 

 prominent median ridge and an acute, smooth, cihated outer margin ; 

 fingers short, not gaping; dactykis a Httle longer than the other 

 finger. Ambulatory feet somewhat hairy. Length of the carapax 

 in the male, 0.26; breadth, 0.235 ; length of hand, 0.36; breadth, 0.18 

 inch. 



Found at Hongkong, China. 



296. PORCELLANA SERRATIFRONS Stimpson 



Plate XXIII, Fig. 2 



Porccllana scrratifrons Stimpson, Proc. xA.cad. Nat. Sci. Phila., x, p. 242 

 [80], 1858. 



Carapax scarcely convex, nearly smooth, glabrous, occasionally 

 pubescent in parts, anteriorly contracted, posteriorly broadly rounded, 

 and slightly striated towards the sides. Lateral margin acute, turn- 

 ing inwards a little on the surface of the carapax at the lateral notch. 

 There is a small, sharp spiniform tooth at the middle of the lateral 

 margin, and sometimes a minute one in front of it, a spine over the 

 insertion of the external antennae, and another minute one just be- 

 hind the external angle of the orbit, which is acute. Beneath this 

 angle there is another spine. Front tridentate ; teeth prominent, 

 triangular ; middle tooth largest, but not much more prominent than 

 the others ; margins minutely serrated. The bases of both pairs of 

 antennae are spinuligerous. Latero-inferior or epimeral regions of 

 the carapax strongly striated. Outer maxillipeds transversely stri- 

 ated ; meros longer than the ischium. Chelipeds of the male glab- 

 rous, punctated ; angle of the meros prominent, minutely bidentate ; 

 carpus three-toothed on each side, with the teeth small, the terminal 

 ones of the series acute ; anterior margin of the carpus sometimes 

 five-toothed ; hand with the median angular ridge generally little 

 prominent and obtuse ; fingers twisted into nearly vertical plane, and 

 pilose within. Smaller hand less twisted than the larger one; its 

 outer margin spinulose ; extremity of immovable finger deeply bifid. 

 Hand of the female pubescent externally and with its median ridge 

 tuberculated. Color in life grayish-brown ; anterior part of carapax, 

 and sometimes the chelipeds, mottled with dark blood-red. Length 

 of the carapax in the male, 0.32; breadth, 0.32; length of greater 

 hand, 0.53 ; breadth, 0.19 inch. 



Dredged in the circumlittoral zone in the harbor of Hongkong. 



