308 lin.LETIX 97, UNITED STATES NATIONAL MUSEUM. 



Side margins of male abdomen sinuous. Appendages of first 

 segment widened behind the tips. 



Allied to S. cinereum- and S. miersii. It differs from both in the 

 front having parallel sides instead of widening below, in the fingers 

 gaping, in the male appendages transversely, instead of obliquely, 

 cut at the tip. From /S. cinereum it differs also in its narrower 

 carapace, without scattered tufts of hair, longer fingers, and narrower 

 male abdomen: from S. miersii in the relatively smooth palms, those 

 of miersii being coarsely granulate. 



Measurements, Male holotype, length of carapace 16.1, greatest 

 width of same (at base of second leg) 17.3, width between outer 

 angles of orbit 17.2, width of front 9.4 mm. 



Habitat. Lives in the soft mud of the river banks. 



Range. Known only from the type-locality. 



Material examined. Tampico. Mexico; June 1. 1910: Edward 

 Palmer: 4 males, 1 of which is holotype (45794). 



SESARMA (HOLOMETOPUS) RICORDI Milne Edwards. 



BEACH CRAB. 

 Plate 89. 



Sesartna ricordi MILNE EDWAKDS, Ann. Sci. Nat., ser. 3, Zool., vol. 20. 1853, 



p. 183 [149], (type-locality, Haiti; type in Paris Mus.). 

 Sesarma guerini MILNE EDWAKDS, Ann. Sci. Nat., ser. 3, Zool., vol. 20, 1853, 



p. 183 [149], (" patrie inconnue"; type in Paris Mus.). 

 Sesarma miniata SATJSSTJKE, M6m. Soc. Phys. Hist. Nat. Geneve, vol. 14, 



1858, p. 442 [26], (type-locality, Saint-Thomas; cotypes in Geneva and 



Paris Museums). 

 Sesarma, angustipes STIMPSON, Ann. Lye. Nat. Hist. New York, vol. 7, 1859. 



p. 66 (in part, at least). Not S. angustipes Dana, 1852. SMITH, Trans. 



Connecticut Acad. Arts and Sci.. vol. 2, 1870, p. 159. DE MAN. Notes 



Leyden Mus., vol. 14, 1892, p. 253, pi. 10, fig. 5. 



Sesarma stimi^'iiiii MIEBS, Proc. Zool. Soc. London, 1881, p. 70, (type- 

 locality, Florida and the Tortugas; type in Brit. Mus.). Not S. stimp- 



sonii Miers, 1886. 

 Sesarme cinerea HEILPBIN, Proc. Acad. Nat. Sci. Philadelphia, 1888, p. 320. 



Not Sesarma cinerea (Bosc). 



Sesarma cinerea IVES, Proc. Acad. Nat. Sci. Philadelphia, 1891, p. 181. 

 Sesarma (Holometopus) ricorrfi RATHBUN, Proc. Biol. Soc. Washington, 



vol. 11, 1897, p. 91. 



Diagnosis. Carapace and chelipeds little rough. Third leg twice 

 as long as carapace, merus three times as long as wide. 



Description. Carapace a little wider behind than in front, the 

 length about equal to the anterior width. Surface finely punctate, 

 but granulate only behind the orbits and sparingly on the supra - 

 frontal lobes, and coarsely so on the deflexed surface of the front. 



