CRUSTACEA NORTH PACIFIC EXPLORINX EXPEDITION 143 



latter genus. Its habits, when observed, will throw much light upon 

 its affinities. 



The species of this genus, as far as known, differ from each other 

 by strongly marked characters. 



237. PINNIXA TUMIDA Stimpson 



Pinnixa tumida Stimpsox, Proc. Acad. Nat. Sci. Phila., x, p. 108 [54], 

 1858. 



Of this species three examples are found among our collections, 

 all females, to which the following description will apply : The bodv 

 is transversely cylindrical, and very much swollen. The greatest 

 breadth of the carapax is at the bases of the third pair of ambu- 

 latory feet. Length to breadth as 1:1.83. Surface smooth. 

 There is no antero-lateral crest and no transverse ridge posteriorly, 

 as are seen in most species. The median depression is shallow. 

 Front narrow. Outer maxillipeds closely fitting to each other and 

 to the margin of the buccal area ; palpus large; dactylus attached 

 near the base of the penult joint, overreaching it but little at the ex- 

 tremity, and, like that joint, provided with a long pencil of hairs. 

 Chelipeds moderately large; meros and carpus-joints thickly hairy 

 within; hand externally smooth; fingers gaping; dactylus oblique, 

 with a tooth at the middle ; immovable finger, with minutely ser- 

 rated inner margin and a subterminal tooth forming a notch for the 

 reception of the tip of the dactylus. Ambulatory feet hairy, those 

 of the third pair longest; those of the first and second pairs slender; 

 last two pairs stout and thick ; dactyli slender, with five or six longi- 

 tudinal carins. Female abdomen convex, covering the whole of the 

 sternum with the exception of its posterior corners ; surface along 

 the middle most prominent. 



Color in life: Above blackish, with a few bluish-white spots pos- 

 teriorly and at the sides ; below bluish-white, often inclining to a 

 darker hue, like "neutral tint." Dimensions of the carapax: Length, 

 0.3 ; breadth, 0.55 inch. 



Found in the holes of Caiidiiia (a Holothurian) on sandy beaches 

 in the fourth or lowest subregion of the littoral zone, in the Bay of 

 Hakodadi, Japan. 



238. PINNIXA PENULTIPEDALIS Stimpson 



Pinnixa pcnuUipcdalis Stimpsox, Proc. Acad. Nat. Sci. Phila.. x. p. 106 

 [54]. 185S. 

 Description of the single female specimen : Body rather depressed, 

 and very broad; proportion of length to breadth, i : 2.11. Carapax 



