THE GEAPSOID CRABS OF AMERICA. 45 



Description. Surface coarsely granulate, regions well marked. 

 The fronto-orbital distance is a little less than half the \vidth of 

 the carapace. The front has a large median notch, the two lobes are 

 sinuous, with a distinct but nonprojecting outer tooth. The orbits 

 trend distinctly forward and outward, their inner upper angle is 

 separated by a furrow from the front, the lower angle is acute and 

 prominent, there are two upper fissures and a large V-shaped sinus 

 below the dentiform outer angle. The arcuate antero-lateral margin 

 is upturned and is armed with four strong denticulated teeth, the 

 first of which is the smallest and rather distant from the orbit; below 

 this sinus is a stout subhepatic spinule. Carapace widest at the last 

 tooth. 



Chclipeds of female moderately unequal, rough, with large sharp 

 granules arranged partly in rows. A subdistal spine on upper border 

 of merus; a stout inner carpal spine, with a small spine below it. 

 Dactyl granulate above for half its length, fingers narrowly gaping 

 in the large cknv, a low, stout tooth at base of dactylus. Legs hairy; 

 merus joints spinulous above. 



Dimensions. Female holotype, length of carapace 32.5, width of 

 same 46 mm- 



Material examined. Gulf of California ; off Consag Rock, Lower 

 California; lat. 31 06' 45" N.; long. 114 28' 15" W.; 33 fathoms; 

 bn. M.; temp. 63.8 F.; Mar. 27, 1889; station 3031, Albatross; 2 

 females (1 is holotype) (17465). 



Genus CYRTOPLAX Rathbun. 



Cyrtoplax RATHBUN, Tree. U. S. Nat Mus., vol. 47, 1914, p. 118; type, 

 C. spinidcntata (Benedict). 



Carapace much broader than long, convex longitudinally and 

 transversely. Regions well marked. Antero-lateral margins arcu- 

 ate, dentate; postero-lateral converging. Fronto-orbital width three- 

 fifths of width of carapace. Front advanced, lobes convex, sepa- 

 rated only by a furrow from the orbital margin. Eyes rather slen- 

 der. Basal antennal joint rather broad, inner angle just touching the 

 front ; flagellum standing in the orbital hiatus. Buccal cavity widen- 

 ing distally. Maxillipeds gaping; merus broader than long. 



Chelipeds stout, unequal; wrists subtriangular in dorsal aspect, 

 bispinose ; palms high, finger strongly deflexed. Legs long and slen- 

 der ; dactylus of last pair recurved. 



Neither the first nor the third abdominal segment in the male 

 covers the sternum ; the third to the fifth segments are fused. 



Contains only one species. 



