NO. ii(!2. liUAciryruA collkctei) nv tiik Ai.HATnoss—UATniUN. 591 



ECT/CSTHESIUS, new genus. 

 (V.HTOc.. cxteiiial, ami ixioOffdis, ptTcoptioH by lo«liu<^.) 



AlUcd to (Irapsillus; orbital fiasnre closed; aides two-toothed. 



Carapace smooth; wider and sides raore arcuate than in (Irapsillus; 

 furnished Avith two large teeth on tlie antero lateiiil niaif^in, one at the 

 hiteral an{»le, and one between that and the orbital aufjjle. i'ostero- 

 lateral margins converging. Front broad, slightly bilobed. Orbits 

 shallow, entire; inner fissure closed by the union of the lower orbital 

 margin with the Iront (IMate XIJI, lig. 13); orbit otherwise entire. 

 Peduncular joints of antenna"- short; the second Joint Just reaches the 

 lower coiner oC the front; the third Joint attains the frontal margin. 

 Palatal ridge partially developed, anteriorly obsolete. The antero- 

 external angle of the merus of the outer maxillipeds is laterally pro- 

 duced, and the antero internal angle emarginate (Plate II, fig. 14). 

 Chelipeds unequal, smooth, not enlarged; merus short, margins entire; 

 carpus unispinous; fingers elongate, acute. Ambulatory legs short, 

 last three joints setose; dactyli rather stout. 



82. ECTiESTHESIUS BIFRONS, new species. 

 (Plato XLII, tij,'8. 12-14.) 



Carapace slightly convex in both directions, about three-fourths as 

 long as wide, anterolateral margin arcuate, posterolateral margins 

 sinuous and rapidly converging. Surface smooth, except near the front 

 and lateral teeth, where fine granulation may be detected with the lens. 

 Front nearly half the width of the carapace, slightly arcuate, almost 

 imperceptibly bilobed, edge thin, retreating at the outer angles. Just 

 above, behind, and parallel to the margin, at a, distance of about 0.2 of 

 a millimeter, is a sharp ridge which is slightly interrupted at the median 

 line. Orbit less than half the width of the front; outer angle incon- 

 spi(;uous, not advanced beyond the general outline of the orbital margin. 

 The tooth at the lateral angle of the carapace is situated a little in front 

 of the middle of the length of the carapace and is subacute. The first 

 toothof theaiitero-lateriil margin is about one-third the distance between 

 the orbital angle and the lateral tooth and is obtuse. The abdomen of 

 the mature female is narrow; third, fourth, and fifth segments subeciual 

 in length as well as in width; sixth of the same width, but longer; 

 seventh narrower, length and breadth snbequal, extremity rounded. 

 I'eduncular Joints of antennae short. 



Merus of chelipeds extending but little outside the carapace, trigonal, 

 widest near the middle. Carpal tooth large and sharj). Manns with 

 the inner surface swollen toward the proxinial end, as in (irapsUlus ; 

 margins smooth and rounded; superior margin slightly convex, inferior 

 margin sinuous, that of the pollex being concave. Dactylus longer than 

 the superior margin of the palm. Fingers not gaping, marked with a 

 few lines of punctie ; dactylus without teeth ; pollex of the larger cheliped 



