CRUSTACEA NORTH PACIFIC EXPLORING EXPEDITION 1 35 



226. SESARMA PICTA (De Haan) Milne Edwards 



I\icli\'so)iia pictuDi De Haan, Fauna Jap., Crust., p. 61, pi. xvi, lig. 6. 

 Srsanna /'/V/a AIilne Edwards, Mel. Carcin., p. 150. 



Found at Ousima. 



227. SESARMA RUPICOLA Stimpson 



Plate XVII, Fig. i, la, ib 



Scsar)iia nipicola Stimpson, Proc. Acad. Nat. Sci. Phila., x, p. 106 [52], 

 1858. 



Carapax depressed, quadrate, much broader than long; proportion 

 of length to breadth, i : 1.19. Surface very uneven, anteriorly trans- 

 versely rugulose. Anterior gastric lobules well marked ; those of 

 the middle pair with oval spaces at the summits, as if eroded. Frontal 

 region somewhat minutely tuberculated ; frontal margin waved. Lat- 

 eral margins straight, entire, but sometimes with obscure indications 

 of two or three teeth, best seen in a side view. Epistome partly 

 granulated. Chelipeds (of female) of moderate size; inner edge of 

 meros crenulated as far as the triangular tooth at the apex, anterior 

 edge nearly smooth ; surface of carpus with short granulated rugae. 

 Hand on the outer surface smooth toward the extremities, but granu- 

 lated above and posteriorly ; granules small, those of the superior 

 surface arranged in three or four oblique but nearly longitudinal 

 rows, not parallel ; a small, sharp, denticulated tooth on the upper 

 edge of the hand at the base of the dactylus ; inner surface granu- 

 lated, granules scattered ; dactylus ornamented above with two or 

 three longitudinal rows of very small tubercles. Ambulatory feet 

 rather long; meros only moderately dilated; last two joints moder- 

 ately provided with short, stiff hairs. 



In life carapax black, with a few small bluish-white blotches ; feet 

 pale grayish, mottled. Below bluish-grey. Fingers and lower sur- 

 face of the hand pale reddish-white. Dimensions of the female : 

 Length of carapax, 0.78 ; breadth, 0.92 inch. 



It is closely allied to S. affiiiis, but differs from this as well as from 

 S. quadrata in its less dilated meros-joints, from S. picta in its less 

 oblique and non-pectinated crests of the hand and non-plicated fin- 

 ger. There is also no tuberculated ridge on the inner surface of the 

 hand. 



This species dift'ers in its habits from most of the genus Scsanna. 

 It lives among rocks at about half-tide, on shores more or less ex- 

 posed to the surf. Found in Fou-kow Bay, in the island of Ousima. 



