170 BULLETIN 166, UNITED STATES NATIONAL MUSEUM 



Genus LEUCOSILIA Bell 



Leucosilia Bell, Trans. Linn. Soc. London, vol. 21, p. 295, 1855 [type, L. juri?iet 

 (Saussure)]. 



Carapace orbicular, subglobose, front with two divergent teeth; 

 intestinal region unidentate. Antennular fossae oblique, hollowed 

 out of the frontal teeth. Three orbital fissures. Exognath of outer 

 maxillipeds sHghtly curved, margins parallel, apex obtuse. Chelipeds 

 robust, of medium length. Abdomen of male with segments 3-5 

 coalesced, penult segment unispinous; abdomen of female broadly 

 ovate, strongly convex. 



West coast of America; Indian Ocean. 



LEUCOSIUA JURINEI (Sanssnre) 



Plate 48, Figures 1-8 



Guaia {Ilia) jurinei Saussure, Rev. Mag. Zool., no. 8, p. 65 [12], pi. 13, fig. 4-4b, 



1853 (type locality, Mazatlan, Mexico; type in Geneva Mus.). 

 Leucosilia jurinii Bell, Trans. Linn. Soc. London, vol. 2, p. 295, pi. 32, fig. 1, 



1855. — Stimpson, Boston Journ. Nat. Hist., vol. 6, p. 471, 1857; Ann. Lye. 



Nat. Hist. New York, vol. 7, p. 69 [23], 1859. 

 Leucosilia jurinei Rathbun, Proc. U. S. Nat. Mus., vol. 38, p. 552, pi. 45, fig. 1, 



1910.— Boone, Zoologica, vol. 8, p. 283, fig. 100, 1927; Bull. Amer. Mus. 



Nat. Hist., vol. 58, p. 583, fig. 18, 1929. 



Diagnosis. — Surface everywhere granulate; carapace without spines. 

 A short protuberance on intestinal region, two prominences on hepatic 

 region. 



Description. — Carapace convex, sides rounded, surface covered with 

 large contiguous granules except on the frontal and part of the hepatic 

 regions, which are covered with a pavement of minute flattened 

 granules. A low, blunt elevation on hepatic, a triangular prominence 

 on subhepatic region. A stout tubercle or tooth on the intestinal 

 region; posterior margin curved, shghtly projecting. Abdomen of 

 male very long; penult segment shorter than terminal one, its spine 

 overlapping the fused segment; abdomen of female with a broad 

 central carina. Abdomen and sternum coarsely granulate. CheH- 

 peds half as long again as carapace, arm coarsely granulate, wrist and 

 chela finely so; palm short and thick, fingers slightly curved, armed 

 with small denticles on the inner edge; tips crossing. 



Measurements. — IVIale (20672), length of carapace 20, width 18.2 

 mm; female (39102), length 17.5, width 17.6 mm. 



Range. — West coast of Mexico to Peru; Galapagos Islands. 



Material examined. — As follows: 



Mexico: West coast; Forrer collector; 1 male, 1 female (6725, 

 Berlin Mus.). 



Nicaragua: Realejo; Orsted collector; 1 male (20672), 2 males 

 (Copenhagen Mus.). Corinto; J. A. McNiel; 2 females (6449, 

 M. C. Z.). 



