114 BULLETIN 18 7, UNITED STATES NATIONAL MUSEUM 



Phrynonax Cope, Proc. Acad. Nat. Sci. Philadelphia, vol. 14, 1862, p. 348 (type, 

 Tropidodipsas lunulatus Cope). — Amaeal, Mem. Inst. Butantan, vol. 4, 1929, 

 pp. 301-320, figs. 1-6 (a brief generic revision). 



Genotype. — Dipsas dieperinkii Schlegel l=Pseustes sulphureus 

 sulphureus ( Wagler) ] . 



Range. — From central Veracruz along the Atlantic coast through 

 Central America and southward in South America to Bolivia and 

 southern Brazil. 



Species. — Two species, including seven subspecies, are recognized. 

 Only two races (one species) occur in Mexico. 



KEY TO MEXICAN FORMS OF PSEUSTES 



(Adults only) 



1. Each dorsal scale with a conspicuous light center ; a narrow, longitudinal 



dark line on each side of middorsum poecilonotus argus 



Light spots scattered ; dim, oblique dark lines on sides of body ; no 

 paravertebral dark stripes poecilonotus poecilonotus 



PSEUSTES POECILONOTUS POECILONOTUS (Gunther) 



Spilotes poccilonotms Gunthek, Catalogue of the snakes in the British Museum, 



1858, p. 100; Biologia Centrali-Americana, Rept. Batr., 1894, pp. 117-118, 



pi. 43. 

 Phrynonax poecilonotus poecilonotus Gaige, Carnegie Inst. Washington PubL 



No. 457, 1936, p. 299. 

 Pseustes poecilonotus poecilonotus Schmidt, Publ. Field Mus. Nat. Hist., zool. 



ser., vol. 22, 1941, pp. 499-500. 



Type.— Bv'ii. Mus. Nat. Hist. 

 Type locality. — "Honduras." ^® 



Range. — The Yucatan Peninsula, eastward to western Honduras 

 (known in Mexico only from Chichen Itza, Yucatan) , 



PSEUSTES POECILONOTUS ARGUS (Bocourt) 



Spilotes argus Bocouet, Mission scientifique au Mexique et dans I'Am^rique 



centrale. Kept., livr. 11, 18SS, pp. 692-693, pi. 48, fig. 10.— GiJNTHEB, Biologia 



Centrali-Americana, Rept., 1894, pp. 118-119, pi. 44. 

 Phrynonax guentheri Boulenger, Catalogue of the snakes in the British Museum, 



vol. 2, 1894, pp. 20-21 (type locality, Atoyac, Veracruz; type in Brit. Mus. 



Nat. Hist). 

 Pseustes poecilonotus argus Smith, Proc. U. S. Nat. Mus., vol. 93, 1943, pp. 



462-463. 



Type. — Mus. Eoy. Hist. Nat. Brussels. 

 Type locality. — Mexico. 



Range. — Atlantic slopes from central Veracruz southward into 

 Guatemala, excluding the Yucatan Peninsula (known in Mexico from 



6' Schmidt (op. cit.) gives reasons to believe tbat the type locality actually is British 

 Honduras, stated by error as Honduras. 



