482 BULLETIN 152, UNITED STATES NATIONAL MUSEUM 



Parapilunmus Kossmann, Zool, Ergeb. Reise Kiistengeb. Rothen Meeres, 

 Crust., 1877, p. 38; type, P. cristimanus (A. Milne Edwards). 



Carapace and legs generally covered with hair. Carapace trans- 

 versely oval or subquadrilateral, declivous anteriorly, fiat posteriorly, 

 not greatly broader than long; the regions, as a rule, but moderately 

 plainly demarcated and areolated. Antero-lateral borders not longer, 

 but commonly shorter than postero-lateral, and cut into teeth which 

 are often spiniform. Front usually about a third the greatest breadth 

 of carapace, but sometimes broader; cut into two lobes, the outer 

 angle of each of which commonly forms an independent dentiform or 

 spiniform lobule separated from the supra-orbital angle by a groove 

 or notch. The orbits generally have a gap or fissure just below the 

 outer angle, and one or two gaps or notches in the upper border; 

 inner lower orbital angle commonly sharp and prominent. Eyes 

 moderately long and slender. The antennules fold transversely. 

 Basal antennal article short, either not quite touching the front or 

 just touching it by its inner angle; the flagellum, which is planted in 

 the orbital hiatus, is long, usually very much longer than the major 

 diameter of orbit. Ridges of endostome, defining expiratory chan- 

 nels, plain, but not very high; anterior border of merus of external 

 maxiilipeds almost transverse and not notched. Chelipeds stout, 

 the fingers coarse, short, and pointed. Legs usually stout and of 

 moderate length. The abdomen of male consists of seven separate 

 segments. 



Found on the American coasts from North Carolina to Argentina 

 and from San Pedro, California, to Peru. Also inhabits other tropical 

 and warm temperate seas. 



KEY TO THE AMKEICAN SPECIES OF THE GENUS PILUMNUS 



A*. Margin of frontal lobes more or less convex. 



B'. Antero-lateral spines or teeth four, or occasionally three, including the 

 outer orbital one. 

 C^ Ambulatory legs of moderate length, less than twice as long as cara- 

 pace. 

 D^ Palms hairy or partly hairy. 



E'. Major palm partly smooth and bare on outer surface, 



F'. Hair on carapace not covering the whole carapace or 

 not forming so thick a coat as to conceal the surface 

 beneath. 

 G'. Two or more superhepatic spines. AH long spines 



black or dark colored sayi, p. 484. 



G-. No superhepatic spines. 



H'. Major palm smooth on larger part of outer 



surface dasypodus, p. 493. 



H2. Major palm rough on larger part of outer 

 surface. 

 J'. Frontal lobes deep, margins arcuate. 



Orbit unarmed above quoyi, p. 610. 



J*. Frontal lobes shallow. 



