NO. 2047. AMERICAN BRACHYRHYNCH0U8 CRABS— RATHBVN. 



125 



Carapace perceptibly wider than long, of nearly even width 

 throughout, though widening slightly behind. Surface coarsely 

 punctate at the middle, finely punctate on the branchial and intestinal 

 regions, the punctsB more or less connected by fine grooves; surface 

 of frontal region and antero-lateral angles finely granulate; postero- 

 lateral grooves fine. 



Supra-frontal lobes deeply separated, the median groove larger 

 than the lateral grooves; middle pair of lobes transversely arcuate; 

 outer pair narrower, oblique, trending forward toward the orbit. 

 Front relatively broad and low, about 5 times as wide as high, sides 

 vertical, lower margin arcuate in front view, smuous in dorsal view, 

 surface concave it\ both directions. Upper margin of orbit nearly 

 straight, up to the short, acute tooth at the outer 

 angle of the orbit. 



Merusof cheliped covered with granulated rugae 

 on its outer face ; lower outer margin with a well- 

 marked subdistal tooth; tooth on upper margin 

 nearly obsolete; inner margin denticulate, dis- 

 tally expanded and bearing a large tooth. Upper 

 surface of carpus similar to outer surface of 

 merus. Palm massive m the full-grown male, 

 as high as its horizontal length, lower margin 

 arcuate, upper margin marked by interrupted 

 hues of granules ; outer surface covered with fine, 

 depressed granules, inner surface with much larger 

 granules on the more elevated portion. Fingers 

 rather long and slender, for the genus, gaping in 

 the male except at the tip ; prehensile edges den- 

 tate, with 2 or 3 teeth enlarged on each finger. 



Legs of moderate length, the third pair about 

 twice as long as the carapace; merus joints 

 about two and three-fourths tunes as long as 

 wide, converging slightly from the middle to the 

 distal end. 



Side margins of male abdomen sinuous. Appendages of first seg- 

 ment widened behind the tips, which are transverse. 



AUied to S. cinereum (Bosc)^ and S. m^ers^^ Rathbun.^ It differs 

 from both in the front having parallel sides instead of widening 

 below, in the fingers gapmg, m the male appendages transversely, 

 mstead 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'm. the relatively 

 smooth palms, those of miersii being coarsely granulate. 



IG. 4.— Sesarma (IIolo- 



METOPUS) TAMPICENSE, 

 VENTRAL VIEW OF LEFT 

 APPENDAGE OF FIRST AB- 

 DOMINAL SEGMENT OF 

 MALE, X 10. 



1 Grapsus cincreus Bosc, Hist. Nat. Crust., vol. 1, 1802 (an X), p. 204, pi. 5, fig. 1. 



2 Sesarma {Holometopus) miersii Rathbun, Proc. Biol. Soc. Washington, vol. 11, 1897, p. 



