Notes on North American Crustacea. 81 



Hapalog^aster cavicaiida, nov. sp. 



Plate I., fig. Y. 



Body, feet, and abdomen thickly short-setose above. Carapax sub- 

 cordate, much depressed, nearly smooth, somewhat roughened or gra- 

 nulated at the insertions of the setse. Sutures as in H. dentatus. An- 

 terior margin five-toothed ; median and lateral teeth equally prominent 

 and sharp ; teeth just within lateral teeth, small but sharp. No teeth or 

 spines on the lateral margins, with the exception of the two on each 

 side near the middle, at the origins of the sutures. Antennae as long 

 as the carapax ; flagella very slender. Chelipeds thick and strong, but 

 depressed, of the same size and shape as in H. dentatus, but smooth, 

 and without tubercles, like the carapax ; front margin of meros strongly 

 bidentate ; carpus with a tooth at the inner extremity of its anterior 

 margin ; margins of hand smooth. Ambulatory feet broad, much de- 

 pressed, smooth ; their anterior margins densely ciliated and deeply in- 

 cised, forming four or five closely approximated teeth on each joint. 

 Abdomen short, very broad, depressed, folded abruptly upon itself at 

 the third segment and soldered, so that the three joints above next the 

 base are convex, and setose in short fascicles; but the terminal joints 

 below are concave, coriaceous, not setose, and have the segments dis- 

 tinct. The calcareous plates upon the first segment above are small, 

 elongated, widely separated, and have no median plate between them. 

 The plates of the abdomen are thus somewhat like those of Dermatu- 

 rus, but the outer maxillipeds are exactly as described by Brandt for 

 his genus Hapalogaster. The chelipeds are without spines, as in H, 

 Mertensii. 



Brandt, in his diagnosis of the genus, says that the carapax 

 is somewhat leathery, and but little indurated with calcareous 

 matter, but in the present species, as in the Lomis dentata of 

 De Haan, which we have referred to the same genus, the cara- 

 pax is as hard as is usual in Crustacea. 



The length of the carapax in our species is 0*72 ; breadtli, 

 0-83 inch. 



It w^as found at Monterey, Cal., by Mr. A. S. Taylor, 



MAECH, 1859. 6 Ann. Lto. Nat. Hist. Vol. VII. 



