gg BULLETIN 1G6, UNITED STATES NATIONAL MUSEUM 



Eemarks. — Faxon says of the American specimens that in most of 

 them the spine at the external angle of the carapace is long as in 

 Miers' typical form, but is bent outward at a sharper angle, as in 

 his var. rohusta. The outer spine of front is longer in proportion to 

 inner spine and the carapace rather narrower. Legs shorter, while 

 the chela is midway in form between typical gracilipes and var. 

 robusta. 



Color. — Carapace and hmbs covered with an extremely short 

 brownish or whitish pubescence. 



Range. — Pacific coast of Central America; Hawaiian Islands; 

 western Pacific and Indian Oceans, 257 to 1,823 fathoms. 



Material examined. — See table 29, page 97. 



Genus CYMONOMUS A. Milne Edwards 



Cymonomus A. Milne Edwards, Bull. Mus. Comp. Zool., vol. 8, p. 26, 1880 

 (type, C. quadratus A. Milne Edwards). — A. Milne Edwards and Bouvier, 

 Crustaces decapodes provenant des campagnes du yacht V Hirondelle, fasc. 

 7, p. 57, 1894; Mem. Mus. Comp. Zool., vol. 27, p. 80, 1902.— Bouvier, 

 Bull. Soc. Philom. Paris, ser. 8, vol. 9, p. 59, 1898. — Lankester, Quart. 

 Journ. Micr. Soc, new ser., vol. 47, pp. 439, 453, 1903. — Ihle, Die Decapoda 

 Brachyura der Siboga-'ExTpedition, monogr. 39b', p. 118, 1916. 



Carapace squarish, not conceahng the anterior segments of the 

 abdomen. Regions faintly defined except cardiac and postgastric, 

 which are very distinct. The front forms a rostrum and the orbito- 

 antennal border is prominent beyond the anterolateral angles of the 

 carapace ; apart from this there is no indication of orbits or antennular 

 fossae. Eyestalks either fixed or with their mobihty diminished; 

 eyes impigmented and vestigial. Antennules large, unconcealed; 

 antennal peduncle not hidden and its renal tubercle particularly 

 prominent. Buccal cavern large and square, its roof high and not 

 well differentiated from the receding epistome. The external max- 

 iUipeds almost cover the buccal cavern ventrally, extending beyond 

 base of antennal peduncle; merus produced far beyond carpal articula- 

 tion so that it is not much shorter than the ischium; flagellum large, 

 coarse and completely exposed. No afferent brancliial fissure. 

 Chelipeds equal, much shorter, and in male stouter than the crawling 

 legs. First and second pair of true legs very long, especially the 

 dactylus, and are somewhat compressed; third and fourth pair short, 

 dactyli clawlike; not chelate. All segments of abdomen distinct. 

 (After Alcock.) 



Caribbean region; eastern North Atlantic; Indian and western 

 Pacific Oceans. 



