THE CANCROID CRABS OF AMERICA 273 



opening as in the type-specimen, witli the result that the flagellum, 

 which is as long as the eyestalk, is not concealed; three articles of the 

 peduncle are visible and at least seven of the flagellum. 



Ventral surface of crab granulous and eroded, except abdomen and 

 portions against which legs are applied. Abdomen almost smooth. 

 Palpus of endognath folded above merus and only slightly visible in 

 ventral view. 



Chelipeds subequal, thick, outer surface granulate and eroded. 

 Fingers gradually curved downward, very rough with granulation 

 except at the tip; prehensile edges toothed, not gaping; color brown, 

 that of fixed finger running back on palm, further on inner surface 

 than on outer; dactylus longer than superior margin of palm. Legs 

 short, ornamented with granulations similar to those on carapace. 



Measurements. — Male holotype, length of carapace 8.4, width of 

 same 11.4, fronto-orbital width 5.7, width of front 3.6 mm. 



Range. — From Gulf of California, IMexico, to the Galapagos Islands. 



Material examined. — Gulf of California: East of La Paz; lat. 24° 

 11' 30" N., long. 109° 55' 00" W.; 10 fathoms; Sh.; April 30, 1888; 

 station 2828, Albatross; 2 males, holotype and paratype (21581). 



Maria Madre Island, Mexico; 4-10 fathoms; California Academy 

 of Sciences; 1 male (62713); 1 young female, returned. 



Gardner Bay, oft' Hood Island, Galapagos; 15 feet; Wilham Beebe 

 by diving at station 54, Ardurus; one ovigerous female, holotype of 

 Medaeus rugosus (Mus. N. Y. Zool. Soc). 



Genus MEDAEUS Dana 



Medaeus Dana, Amer. Journ. Sci., ser. 2, vol. 12, 1851, p. 125; type, M. ornatus 

 Dana, 1852.— Alcock, Journ. Asiat. Soc. Bengal, vol. 67, 1898, p. 123. — 

 Odhner, Goteborg's K. Vet. Hand., Fjiirde Foljden, vol. 29, No. 1, 1925, 

 p. 81. 



Carapace not very broad, hexagonal, regions well defined and well 

 areolated. Antero-lateral border ascending, cut into about four 

 large teeth with thick tuberculiform tips, and continued beneath the 

 orbits to the angles of the buccal cavern. Fronto-orbital border 

 half, or a little more than half, the greatest breadth of the carapace. 

 Front about a fourth, or a little more than a fourth, the greatest 

 breadth of the carapace, horizontal, rather prominent, notched in the 

 middle line, separated from the supra-orbital margin by a notch. 

 Chelipeds either unequal or subequal, wrists and hands typically 

 covered with large nodules, fingers pointed. Abdomen of male with 

 third to fifth somites fused. 



Indo-Pacific region; tropical America. 

 79856—30 19 



