145. lEiMOEPHODoisr. 53 



nasals as long as broad or a little broader than long, considerably 

 shorter than the prsefrontals ; 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 prseooular, 

 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, 

 Bixth, 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 bufi^ or sandy grey above, uniform or with ill- 

 defined brown variegations or cross-bars ; lower parts white. 



Total length 1870 millim. ; tail 165. 



Egypt to Somaliland. 



:a. S (V. 271 ; C. 75). Nile. Eev. 0. P. Cambridge 



[P.]. 



i. 2 (V. 263 ; C. 76). Beltim. Dr. J. Anderson [P.]. 



e-d. Hgr. (V. 262 ; C. Qizeh. Dr. J. Anderson [P.j. 

 77) &yg. (V. 257; 

 0. 79). 



e. 2 (V. 272 ; C. 72). Tel el Amarna. Dr. J. Anderson [P.' 



/. Hgr. (V.263;C.81). Assouan. Dr. J. Anderson f 



J/. 2 skeleton. Egypt. 



irp.i. 

 , tp.j. 



145. TEIMORPHODON. 



Dipsas, part., Dum. ^ Bibr. Erp. Gin. vii. p. 1133 (1854). 

 Dipsadomorphus, part., Oiinth. Cat. Col. Sn. p. 174 (1858). 

 Trimorphodon, Cope, Proc. Ac. Philad. 1861, p. 297. 

 Eteirodipaas, part., Jan, Elenco sist. Ofld. p. 106 (1863). 



Maxillary teeth 10 or 11, anterior much longer than the posterior, 

 w^hich 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 praeooular. Body 

 <!ompressed ; scales smooth, slightly oblique, with apical pits, in 21 

 to 27 rows ; ventrals obtusely angulate laterally. Tail moderate ; 

 fiubcaudals 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 bands ■ 1. hiscutatus, p. 54, • 



Scales in 21 or 23 rows ; ventrals 205-236 ; 



subcaudals 61-72 2. upsihn, p. 55. 



