PART 1 GARTH : PACIFIC OXYRHYNCHA 349 



Anaptychoides Strand, 1928, p. 40 (name substituted for Anaptychus 

 Stimpson, preoccupied). 



Type: Ala spinosa Lockington, 1877 = A naptychus cornutus Stimp- 

 son, by monotypy. 



Description: Carapace broader than long, not very convex. Lateral 

 margins advanced in the form of toothed lamellae above the base of the 

 legs. Front formed of two pointed horns. Orbit provided above with a 

 projecting tooth. Eyes small and lodged in cavities entirely separated 

 below by the basal article of the external antennae ; the latter wide and 

 provided in front and on the outside with a strong spine advanced nearly 

 as much as the rostral horns. Movable flagellum exposed. Merus of 

 external maxillipeds broader than long; its anteroexternal angle project- 

 ing; its internal angle notched for the insertion of the palp. Exognath 

 broad and provided on the inside with a triangular sharp tooth lodged 

 between [the second and third article] of the endognath. Ambulatory 

 legs short and heavy. (After A. Milne Edwards) 



Abdomen seven-segmented. 



Range: West coast of America from Cholla Bay, Gulf of California, 

 to Port Utria, Colombia. Shore to 12 fathoms. 



Contains only one species. 



Ala cornuta (Stimpson), new combination 

 Plate V, Figs. 1, 2; Plate 39, Fig. 2 



Anaptychus cornutus Stimpson, 1860b, p. 184, pi. 2, figs. 1, la, lb. 



A. Milne Edwards, 1875, p. 67, pi. 19, figs. 1, la, lb. Streets and 



Kingsley, 1877, p. 105. Kingsley, 1879a, p. 146. Rathbun, 1924c, p. 



379; 1925, p. 378, pi. 134, figs. 4, 5; pi. 254, fig. 1 ; text-fig. 122. 



Steinbeck and Ricketts, 1941, p. 467. Crane, 1947, p. 72. Garth, 



1948, p. 28. 

 Ala spinosa Lockington, 1877c, p. 66; type locality, La Paz, San Jose 



Island, and Port [Puerto] Escondido, Gulf of California; types 



not extant. 

 Mitrax trigonopus Cano, 1889, p. 183, pi. 7, fig. 8; type locality, 



Panama; type originally in Naples Museum, believed not extant. 

 Anapthychus cornutus, Bouvier, 1895, p. 8. 

 Mithrax trigonopus, Rathbun, 1910, p. 575. 



Type: Male holotype, length 25.4 mm, width 31.5 mm, not extant; 

 ovigerous female, paratype, M.C.Z. No. 331. 



Type locality: Pinacate Bay, near Guaymas, Sonora, Mexico; Capt. 

 C. M. P. Stone, collector. 



