528 BULLETIN 129, UNITED STATES NATIONAL MUSEUM 



Subgenus Pseudolambrus Paulson 



Pseudolambrus Favlson, Investig. Crust. Red Sea, vol. 1, 1875, p. 9; type, 



P. calappoides (Adams and White). 

 Parthenolambrus A. Milne Edwards, Crust. R6g. Mex., 1878, p. 148; 



type, P. tarpeius (Adams and White). 

 Parihenopoides Miers, Journ. Linn. Soc. London, Zool., vol. 14, 1879, p. 



672; type, P. massena (Roux). 



Carapace semielliptical or semicircular, with a nearly straight pos- 

 terior margin, the postero-lateral angles being strongly produced. 

 Chelipeds of no great length, never sharply serrate, and with the 

 arms and hands indefinitely contorted. Rostrum more or less de- 

 flexed. (Alcock.) 



PARTHENOPE (PSEUDOLAMBRUS) TRIANGULA (Stimpson) 



Plate 278, figs. 1-3 



Lamhrus triangulus Stimpson, Ann. Lye. Nat. Hist. New York, vol. 7, 

 1860, p. 201 (type-locality. Cape St. Lucas; type not extant). — A. Milne 

 Edwards, Crust. R^g. Mex., 1878, p. 152, pi. 31, figs. 1-lc. 



Diagnosis. — ^Antero-lateral margins oblique and nearly straight, 

 without an angle. Base of movable part of antenna protected by 

 an over-arching tooth on each side, one on orbit, the other on epis- 

 tome. Upper margins of palm 8- or 9-toothed. 



Description. — Carapace an equilateral triangle, posterior margin 

 nearly straight and scarcely exceeding antero-lateral sides in length; 

 this results from the strong projection of the dentated posterior cor- 

 ners of the branchial regions which almost conceal the ambulatory 

 feet. Antero-lateral margin with about 12 very small granulated 

 teeth of which 3 are on the small rounded hepatic region. Surface 

 ornamented with conical tubercles variable in number and size. Ros- 

 trum prominent, obtuse, triangular. Base of movable part of ex- 

 ternal antennae protected on each side by an over-arching tooth, 

 one arising from the lower margin of the orbit, the other from an- 

 terior corner of epistome. Ischium of outer maxilhpeds granulated, 

 merus tuberculated. Chehpeds rather short, strongly angular and 

 dentated; hand granulated below, but nearly smooth above between 

 the crests, which are high and unevenly 8- or 9-toothed ; teeth den- 

 ticulated, middle one largest. Legs smooth and glabrous; dactyli 

 pubescent. (After Stimpson.) 



Measurements. — Female, holotype, length of carapace 14, width of 

 same 17.5 mm. 



Record of locality. — Cape St. Lucas, Lower Cahfornia, Mexico; 

 John Xantus, collector; type not extant. 



