THE GEAPSOID CRABS OF AMEBICA. 37 



Color. — Fingers brown at tip. 



Measurements. — Male holotype, length of carapace 6.9, width of 

 same 11.2, width of front 44 mm. 

 Range. — ICnown only from Panama. 



Genus CHASMOPHORA Rathbun. 



CMsmopliora Rathbun, Proc. U. S. Nat. Mus., vol. 47, 1914, p. 119; t3T>e, 

 C. macrophthalma (Rathbun). 



Carapace very broad, siibcylindrical, very convex longitudinally, 

 much less so transversely; antero-lateral margin short, dentate. 

 Fronto-orbital border about four-fifths the width of the carapace. 

 Front separated from the orbital angle by a furrow. Ej^es stout, 

 filling the orbit; lower margin of orbit with a large outer sinus. 

 Basal joint of antennae not reaching the front, flagellum standing 

 in the orbital hiatus. Buccal cavity widening a little anteriorly; 

 merus of maxillipeds with outer distal angle prominent. 



Eight cheliped of medium size (left not known). Legs slender. 

 First segment of abdomen of female Aery broad, but not covering 

 the whole width of the sternum; third segment narrower. It is 

 probable that in the male these segments have a similar relation to 

 the sternum. 



Near Euryplax.^ from which it is separated by the antennae enter- 

 ing the orbit. 



Contains only one species. 



CnASMOPHORA MACROPHTHALMA (Rathbnn). 



Eucratopsis macroplithahna Ratiirun, Proc. U. S. Nat. Mus., vol. 21, 1898, 

 p. GOl. pi. 43, figs. 3 and 4 (t.vpe-locality, Panama Bay, 51 J fathoms; 

 holotype female, Cat. No. 21501, U.S.X.M.), 



Cliasmophora macrophthalma Rathbun, Proc. U. S. Nat. Mus., vol. 47, 1914, 

 p. 119. test-fig. 2. 



Diagnosis. — Antennae entering the orbit. Buccal cavity anteriorly 

 widened. Eyes large, filling orbit. Carapace broad, subcylindrical. 



Description. — Length three-fifths of breadth. Regions plainly 

 marked. Surface nearly level transversely for the middle two- 

 thirds, deflexed toward the margins; teeth directed obliquely up- 

 ward. Front about one-third the width of the carapace, lobes 

 slightly convex. Superior margin of orbit sloping backward and 

 outward. Three large subequal antero-lateral teeth, including the 

 orbital tooth, acute and curved slightly forward; behind the last 

 a minute tooth or notch. 



The arm is granulated toward the margins, which are unarmed. 

 Carpus finely granulated, with an anterior submarginal sulcus and 



