NOTES ON WEST AMERICAN CRUSTACEA. 



BY SAMUEL J. HOLMES. 

 With Plates xx, xxi. 



Order DECAPODA. 

 Suborder BRACHYURA. 



Family PINNOTHERIDiE. 



Pinnotheres nudus sp. nov. 



Carapax a little broader than long, subquadrate to or- 

 bicular in outline, convex, curving downwards towards 

 all the margins; the surface is smooth and naked, and 

 the regions not defined. Front deflexed, rounded, not 

 protruding, the central portion continued downward as a 

 triangular process between the antennules, while there 

 are smaller triangular processes at the sides partly sepa- 

 rating the orbits from the antennulary fossettes. Orbits 

 ovate, the rather wide inner hiatus partly filled by the 

 base of the antennae; eye peduncles very short and stout, 

 the cornea minute. Antennules oblique; the antennular 

 fossettes communicate with each other beneath the front. 

 Maxillipeds oblique, neatly fitting the buccal area; the 

 meros broad, smooth, subquadrate, the outer margin pro- 

 duced into a broadly rounded laminate expansion; the 

 penultimate joint is oblong, distally rounded; the last 

 joint is spatulate, articulated near the base of and extend- 

 ing somewhat beyond the preceding one. Chelipeds mod- 

 erate, smooth, nowhere furnished with spines or teeth; 

 hands narrow, rather thick, and widest immediately be- 

 hind the articulation of the dactyl; fingers nearly or quite 

 as long as the palm, subconical, and not conspicuously 

 dentate on the inner margins. The three anterior pairs 

 of ambulatory legs are subequal; the fourth pair is smaller; 

 all are smooth, little compressed, and have acute, nearly 

 straight tarsi, those of the fourth pair being relatively 



2d Ser., Vol. IV. March 20, 1894. 



