STREPTOPHORUS.—CHERSODROMUS. 103 
Streptophorus bifasciatus, Dum. & Bibr. Erpét. vii. p. 520; Giinth. Col. Sn. p. 16; Cope, Proc. Ac. 
N. Sc. Phil. 1861 (1860), p. 77; Jan, Arch. per la Zool. ii. p. 26 (1862) ; Bocourt, Miss. 
Sc. Mex., Rept. p. 545, t. 82. figg. 10, 10a, b. 
Hab. Mxxico, Huatusco in Vera Cruz (G. & S.), Orizaba (Sumichrast), Jalapa (Cope), 
Teapa in Tabasco (H. H. Smith), Oaxaca (Hoge). 
Head rather depressed, not distinct from neck. Anterior frontals small. Six upper 
labials, the third and fourth entering the orbit, two postoculars. Temporals 1+-2. 
Two pairs of chin-shields. Scales strongly keeled; in nineteen rows. Ventrals 149-160 ; 
anal entire. Upper parts black, with a yellow collar across the neck, lower parts white ; 
each ventral scute with a subtriangular black spot, the spots forming a chain-like band 
along the middle of the abdomen. 
CHERSODROMUS. 
Chersodromus, Reinh. Vid. Meddel. naturh. Foren. Kjébnh. 1860, p. 242. 
Opisthiodon, Peters, MB. Ak. Wiss. Berl. 1861, pp. 460, 617. 
This genus is closely allied to Streptophorus, from which it differs not only by having 
the two posterior frontals confluent into a single shield, but also by its dentition, the 
maxillary being very narrow and edentulous in front, dilated behind and armed with 
small teeth of equal size. 
1. Chersodromus liebmanni. 
Chersodromus liebmanni, Reinh. Vid. Meddel. naturh. Foren. Kjébnh. 1860, p. 242; Jan, Arch. per 
la Zool. 1862, p. 25, and Iconogr. Ophid. xii. t. 3. fig. 2; Bocourt, Miss. Sc. Mex., Rept. 
p. 552, t. 34. figg. 8, 8 a-e. 
Ninia liebmanni, Garman, Mem. Mus. Comp. Zool. viii. no. 3, p. 95 (1888). 
Opisthiodon torquatus, Peters, MB. Ak. Wiss. Berl. pp. 461, 617. 
Hab. Mexico, Huatusco (G. & S.), Vera Cruz (Smiths. Inst.), Huanusco (Mus. Berol.) 
Scales keeled, in seventeen rows; ventrals 130-134; anal entire; subcaudals 42. 
Seven upper labials, of which the third and fourth enter the orbit. Black above, 
whitish below, mottled with black, more especially on the hinder part of the body. A 
yellow band across the occipitals. 
2. Chersodromus nigricans. 
Chersodromus nigricans, Reinh. Vid. Meddel. naturh. Foren. Kjébnh. 1860, p. 245. 
Hab. * CENTRAL AMERICA. 
Uniform dark brown; ventral shields 131; subcaudals 41. 
Probably not specifically distinct from the preceding. The locality whence the type 
was obtained is not recorded, but it was probably Central America. 
