145. TRIMORPHODON, 53 
masals as long as broad or a little broader than long, considerably 
shorter than the prefrontals ; frontal about once and a half as long 
as broad, as long as or a little longer than its distance from the end 
of the snout, shorter than the parietals ; nasal divided; loreal once 
and a half to once and three fourths as long as deep ; one preocular, 
in contact with or narrowly separated from the frontal; two post- 
oculars; temporals small, scale-like, 2+ 2, 3, or 4; nine to eleven 
upper labials, third, fourth, and fifth, fourth, fifth, and sixth, or fifth, 
sixth, and seventh entering the eye; three to five lower labials 
in contact with the anterior chin-shields; posterior chin-shields 
small and widely separated from each other, or indistinct. Scales 
in 23 (rarely 21) rows. Ventrals 213-272; anal divided ;‘sub- 
caudals 65-82. Pale buff or sandy grey above, uniform or with ill- 
defined brown yariegations or cross-bars; lower parts white. 
Total length 1870 millim. ; tail 165. 
Egypt to Somaliland, 
a. & (V. 271; C. 75). Nile. Rev. O. P. Cambridge 
Fi. 
b. 2 (V. 263; C. 75). Beltim. pit J ieee, Py. 
c-d. Hgr. (V. 262; C. Gizeh. Dr. J. Anderson LP. ; 
77) & yg. (V. 257; 
C. 79). — 
e. 2 (V. 272; C. 72). Tel el Amarna. Dr. J. Anderson [P.], 
J. Her. (V. 263 ; C. 81). Assouan, Dr. J. Anderson | P.}, 
g- & skeleton, Egypt. 
145. TRIMORPHODON. 
Dipsas, part., Dum. §& Bibr. Erp. Gén. vii. p. 1133 (1854). 
Dipsadomorphus, part., Giinth. Cat. Col. Sn. p. 174 (1858). 
Trimorphodon, Cope, Proc. Ac. Philad. 1861, p. 297. 
Eteirodipsas, part., Jan, Elenco sist. Ofid. p. 105 (1863). 
Maxillary teeth 10 or 11, anterior much longer than the posterior, 
which gradually decrease in size, followed, after an interspace, by a 
pair of enlarged grooved teeth situated below the posterior border of 
the eye ; anterior mandibular teeth strongly enlarged. Head distinct 
from neck; eye moderate, with vertically elliptic pupil; loreal 
usually divided; usually a subocular below the preocular. Body 
compressed ; scales smooth, slightly oblique, with apical pits, in 21 
to 27 rows; ventrals obtusely angulate laterally. Tail moderate; 
_ subcaudals in two rows. 
Lower California, Arizona, Mexico, Central America, 
Synopsis of the Species. 
I. Eight or nine upper labials. 
Scales in 25 (rarely 23 or 27) rows; ventrals 
234-264; subcaudals 74-94; head with 
chevron-shaped hands .............4.- 1. biseutatus, p. 54. 
Scales in 21 or 23 rows; ventrals 205-236 ; 
pabonndale GET ee on Secs sce saan 2. upsilon, p. 55. 
