68 CALIFORNIA ACADEMY OF SCIENCES. 



reaches the infero-lateral frontal process. Endostome plainly carinated. 

 Pterygostomian regions more or less granulated. Chelipeds unequal, 

 setose; merus scarcely as long as high, the margins finely denticulated; a 

 spine at the supero-distal angle separated from a similar spine behind by 

 a deep notch; outer surface of the carpus thickly covered with spines; 

 upper and outer surface of the hand covered with several series of spines; 

 lower margin finely denticulated; fingers dark colored. Legs setose; 

 carpus and propodus armed above with spines; merus with a spine at the 

 supero-distal angle; dactyls hairy, nearly straight, and subequal to the pro- 

 podi. Terminal segment of the abdomen in the male triangular. 



San Diego, California (Lockington's type)! Mulege 

 Bay, Gulf of California! 



Appendix to the XANTHINI Ortmann. 

 Genus Tel^messus White. 



Carapace depressed, subpentagonal, broader than long and covered with 

 setse. Front wide, the median portion cut into four teeth and separated 

 by a sinus from the lateral pxjrtions which form the preorbital teeth. The 

 antero-lateral and postero-lateral margins are dentate and meet each other 

 at an angle. Orbits large; postorbital tooth prominent. Antennules 

 folded longitudinally or nearly so in wide fossettes. Epistome with a 

 triangular point extending forward between the antennules. Basal anten- 

 nal joint broad, forming a part of the outer wall of the antennulary fossettes 

 and produced on the outer side into a lobe which occupies the inner hiatus 

 of the orbit; flagellum quite long. Maxillipeds produced a little beyond 

 the anterior margin of the buccal area; the merus has a more or less tri- 

 angular apex and bears the palp on the inner margin just behind the tip. 

 Chelipeds setose and scabrous or spinous and rather short in both sexes; 

 merus trigonous; hands compressed and furnished with spinous or tuber- 

 culated ridges on the outer surface. Legs quite long, compressed, sca- 

 brous or spinose; dactyls long, compressed, acute. Abdomen of the female 

 seven-jointed, the sides of the sixth joint concave, leaving the genital 

 openings exposed. Abdomen of the male widest at the third segment and 

 having the third, fourth and fifth joints fused. 



Type. — 2\ cheiragonus (Tilesius). 



Unless Latreille's bare mention in a list of genera of 

 the name Gheiragone ^ without referring to it any species 



1 Families nat. a Paris, 1826, p. 270. 



