38 BULLETIN 199, UNITED STATES NATIONAL MUSEUM 



Studies on the cranial anatomy may reveal differences not now 

 apparent. 



Range. — The southern tip of Baja California, Arizona, the Rio 

 Balsas Valley, and southern Guerrero. 



Genus BIPES Latreille 



Bipes Latrkille, Histoire naturelle des reptiles, vol. 2, 1802, p. 90. 



Bimanus Oppel, Die Ordnungen, Familien und Gattungen der Reptilien . . ., 



1811, p. 18. 

 Hemichirotes DuGfes, in Cope, Amer. Nat., vol. 28, 1894, p. 436 (type, Hemichirotes 



tridactylus Duges). 

 Euchirotes Cope, ibid, (type, Euchirotes biporus Cope). 



Genotype. — Bipes canaliculaius Bonnaterre. 



Range. — Baja California, Guerrero, southeastern Arizona. 



Species. — Three. 



KEY TO SPECIES OF BIPES 



1. Digits 5 2 



Digits 3, clawed tridactylus (p. 38) 



2. All digits equally developed, all generally with claws; 6 preanal pores. 



canaliculatus (p. 38) 

 One digit smaller and lacking claw; 2 preanal pores biporus (p. 38) 



BIPES TRIDACTYLUS (Dugfes) 



Hemichirotes tridactylus DuGfcs, in Cope, Amer. Nat., vol. 28, 1894, pp. 436-437, 

 fig. 6; La Naturaleza, ser. 2, vol. 2, 1894, pp. 411-412, pi. 20. 



Bipes tridactylus, Smith and Neckeh, Anal. Esc. Nac. Cien. Biol., vol. 3, 1943, 

 pp. 196-197. 



Type. — Alfredo Duges Mus., Guanajuato, Guanajuato, Mexico. 

 Type locality. — Tecpan de Galeana, Guerrero. 



Range. — Known only from type locality (only the type specimen 

 known). 



BIPES BIPORUS (Cope) 



Euchirotes biporus Cope, Amer. Nat., 1894, p. 437, figs. 5-5e; Ann. Rep. U. S. Nat. 



Mus., 1898 (1900), pp. 680-682, fig. 140. 

 Bipes biporus, Stejnegek and Barbour, Check list of North American amphibians 



and reptiles, 1917, p. 72. 



7V2>e.— U.S.N. M. No. 8568, cotypes (?), T. H. Street collector, and 

 No. 12599, 12 specimens, L. Belding collector. 



Type locality. — Cape San Lucas, Baja California. 



Range. — The cape region of southern Baja California. Reported 

 from La Paz, Cape San Lucas. 



BIPES canaliculatus Bonnaterre 



B{ipes\ canaliculatus Bonnaterre, Encyclopedic m^thodique, Erp^tologie, 1789, 



p. 68, pi. 12. 

 Bipes canaliculatus, Sonnini and Latreille, Histoire naturelle des reptiles, vol. 2, 



1801, p. 90.— Smith, Journ, Washington Acad. Sci., vol. 39, 1949, pp. 42-43. 



