314 BULLETIN 97, UNITED STATES NATIONAL MUSEUM. 



those of median pair only a little wider than those of lateral pair; 

 lobes prominent, as if arising from lower margin of front, armed 

 with rather acute granules; deflexed part of front concave and 

 granulous. Anterior part of carapace granulate; granules elongate, 

 sub-squamiform, consisting of a linear series of two to five small 

 granules, bearing now and then minute setae, visible only with a lens 

 in the adult. Posterior part of carapace, except of branchial region, 

 without granules but appearing punctate; in the young the punctae 

 are beset with hair. Small transverse folds cross the posterior part 

 of the branchial region. 



General aspect of carapace rather flat, only feebly convex ante- 

 riorly. Mesogastric sulcus narrow, but reaching front ; on each side 

 a short sulcus runs at right angles toward the supero-internal angle 

 of the orbit. Gastro-cardiac sulcus deep. 



Chelipeds rather slender. Merus outwardly rugose, its upper 

 angle acute and denticulate ; lower angle also conspicuously denticu- 

 late ; infero-inner angle dilated toward the apex and bearing a rather 

 large tooth or denticulate projection. Carpus coarsely granulous, 

 without inner tooth or prominence. Hand rather swollen, covered 

 outside with rather large granules; granules of inner surface much 

 depressed and less crowded ; no trace of an inner crest ; upper margin 

 limited by a denticulate crest. Palm shorter than fingers; the latter 

 are slightly dentate, leave a small gape when closed, the apices horny 

 and slightly excavate. 



Legs long and slender ; penult pair notably longer than the others. 

 Merus from two and one-half to three times as long as its width, 

 the propodus one and one-half times as long as the dactylus. All 

 the articles bear a small, denticulate crest above and are freely 

 squamose on the posterior surface; the merus has at its extremity a 

 stout, acute tooth directed forward. Dactylus and distal end of 

 propodus bear a few short setae. (After Nobili.) 



Measurements. Male cotype, length of carapace 7, width of same 

 at second ambulatory legs 8, width between exorbital angles 8, 

 width of front 4.5 mm. 



Range. Colombia (Pacific coast) and Ecuador. 



SESARMA (HOLOMETOPUS) ANGUSTUM Smith. 



Plate 92. 



Sesarma angusta SMITH, Trans. Connecticut Acad. Arts and Sci., vol. 2, 

 1870, p. 159 (type-locality, Pearl Islands, Bay of Panama; male holo- 

 type, Cat. No. 659, P.M.Y.U.). 



Diagnosis. Longer than wide. Chelipeds small. Merus joints of 

 legs diminishing slightly from middle to distal end. 



