oe. a t= 
212 COLUBRID. 
prefrontals; frontal longer than broad, longer than its distance 
from the end of the snout, shorter than the parietals ; nasal entire ; 
loreal a little longer than deep; one pre- and two postoculars ;. 
temporals 142; seven upper labials, third and fourth entering the 
eye; four lower labials in contact with the anterior chin-shields, 
which are longer than the posterior. Scales in 15 rows. Ventrals. 
152-170 ; anal divided ; subcaudals 37-45, Red above, with pairs 
of black cross-bars enclosing yellow ones ; a large black spot on the 
head, behind the snout; lower parts whitish. 
Total length 285 millim.; tail 55. 
Mexico. 
a-b. 5d (V. 166; ©. 45) Mezquital del Oro, Dr. A. OC. Buller [C.].. 
& 2 (V. 170; C. 42). 
3. Scolecophis emulus. 
Procinura seemula, Cope, Proc. Amer. Philos. Soc, xviii. 1879, p. 262. 
Rostral visible from above; frontal broad, acutely pointed 
behind ; parietals short ; nostril between two nasals; loreal quad- 
rangular ; one pre- and two postoculars; temporals 14+2; seven 
upper labials, third and fourth entering the eye; anterior chin- 
shields much longer than the posterior. Scales in 15 rows, keeled. 
on the posterior dorsal region; caudal scales keeled, tubercular. 
Ventrals 148 ; anal divided; subcaudals 41. Body encircled with 
black annuli, which are broadly bordered with yellow and separated 
by red interspaces of twice their width ; the red scales with a central. 
black spot; a large black spot covering the frontal, parietal, and 
supraocular shields. 
Total length 364 millim. ; tail 61. 
Southern Chihuahua, Mexico. 
184, HOMALOCRANIUM. 
Duberria, part., Fitzing. N. Class. Rept. p. 29 (1826). 
Cleelia, part., Wagl. Syst. Amph. p. 187 (1830). 
Calamaria, part., Schleg. Phys; Serp. ii. p. 25 (1837). 
Homalocranium, part., Dum. §& Bibr. Mém. Ac. Se, xxiii. 1853, 
Pp. 18 (1858), Gén. vii. p. 855 (1854); Giinth. Cat. Col. Sn. 
Tantilla, Baird § Gir. Cat. N. Am. Rept. p. 181 (1853) ; Cope, Proc. 
U.S. Nat. Mus. xiv. 1892, p. 597. 
Lioninia, Hallow. Proc. Ac. Phitad. 1860, p. 484, 
Homalocranium, Jan, Arch. Zool, Anat, Phys. ii. 1862, p. 50;. 
Bocourt, Miss. Sc. Mex., Rept. p. 778 (1883). 
Microdromus, Giinth. Ann, § Mag. N. H. (4) ix. 1872, p. 17. 
Pogonaspis, Cope, Proc, Ac. Philad, 1894, p. 204. 
Maxillary teeth small, equal, 12 to 14, followed by a pair of 
feebly-enlarged grooved teeth, situated below the posterior border 
of the eye; mandibular teeth equal. Head small, not or but 
slightly distinct from neck; eye small, with round pupil; no loreal 
