118 )S. T. Smith on American Crustacea. 



Academy of Science, all obtained at the Gulf of Fonseca, west coast 

 of Central America, by J. A. McNiel. 



This species is apparently closely allied to the G. styliferus, but 

 the ocular stylets in that species are very short, and the hand, as 

 figured by Edwards, is shorter and higher in proportion than in our 

 species. The description of G. styliferus is, however, too short to 

 permit of a detailed comparison of the species. 



Gelasimus styliferus Edwards. 



G'etosmMS^Zail/dociyZMs Edwards, Regne animal de Cuvier, 3™e ^(jit.j Crust, pi. 18, 

 fig. 1 ''■, Tion Histoire naturelle des Crust, tome ii, p. 51, 1837, {teste Edwards). 



Gelnsimus styiferus Edwards, Annales des Sciences naturelle, 3™«' serie, Zoologie, 

 tome xviii, 1852, p. 145, pi. 3, fig. 3. 



The following is the description given by Edwards : — '• Espece tr6s 

 voisine du G. platy dactyl a s.^ mais ayant le Crete marginale du bras 

 moins developpee et les podophthalmites tei-mines par un petit stylet 

 comme chez les Ocypodes. — Guayaquil." 



Gelasimus heteropleurus, sp. nov. 



Plate II, figure 7. Plate III, figure 2-2". 



Male. The carapax is quadrilateral in outline, but the antero-lateral 

 angle on one side is produced as in G. heterophthalmus. The dorsal 

 surface is slightly granulous, quite flat anteriorly and only slightly 

 convex posteriorly. The branchial regions are not at all swollen but 

 are separated from the gastric and cardiac regions by deep sulci. The 

 front is spatulate and expanded below the bases of the ocular pedun- 

 cles. The superior border of the orbit is arcuate in the middle and 

 has an upturned and slightly crenulated margin. The antero-lateral 

 angle, on the side of the smaller cheliped, is acute and projects slightly 

 forward, while on the side of the larger cheliped, it projects laterally 

 as a very prominent obtuse tooth. The lateral margins are angular 

 and armed with a very marked line of sharp granules. The upper 

 part of the inferior branchial region is smooth and nearly perpen- 

 dicular. The inferior border of the orbit is thin and denticulate with 

 minute, flattened and truncate teeth. The jugal regions are granulous. 



The ocular i)eduncles are slender, much enlarged at the cornea and 

 the one on the side of the larger cheliped is much longer than the 

 other and is terminated by a slender flattened stylet about as long as 

 the cornea. 



In the larger cheliped, the anterior surface of the merus is narrow, 

 somewhat convex, and smooth, its margins are minutely denticulate, 

 3nd the superior one is armed with a narrow crest-like process at the 



