276 ANGUIDS. 
twice and a half as long as head and body; upper caudal scales 
usually much less strongly keeled than dorsals. Brown or brownish 
olive above, with darker brown spots or with more or less regular 
cross bands of black and whitish spots; a series of black vertical 
bars or annuli in the lateral fold; usually a yellowish streak, some- 
times bordered with black above, from below the eye to the angle of 
the mouth ; lower surfaces yellowish or greenish white, uniform or 
speckled with black. 
millimh, millim 
Total length ...... 403 Fore limb........ 39 
Head ............ 29 Hind limb........ 46 
Width of head .... 18 Hi ar ee 270 
BOO Y- is see ae a gals 104 
Western North America and Mexico. 
ad. Cordova M. Sallé [C.] 
b. Her. Mexico. M. Sallé [C.]. 
0d. O. Mexico. 
e-k, Ad. & her. ? 
14. Gerrhonotus modestus. 
Pterogasterus modestus, Cope, Proc. Am. Philos. Soc. xvii. 1877, 
p. 97; Giinth. Le. p. 42. 
Differs from Gt. liocephalus in the absence of the small canthal 
shield which truncates the lateral angle of the odd prefrontal, and 
in the absence of keels on the dorsal scales, which are in ten or 
twelve longitudinal series. Upper caudal scales strongly and 
obtusely keeled. Colour above, brown; below, olivaceous ; sides 
reddish-brown or maroon, bordered above by a blackish line which 
separates it from the dorsal colour. 
Total length 150 millim.; length to vent 72 millim. 
Guatemala ? 
15. Gerrhonotus rhombifer. 
Gerrhonotus rhombifer, Peters, Mon. Berl. Ac. 1876, p. 298; Giinth. 
le. p. 42. 
—— (Abronia) rhombifer, Bocourt, Miss. Se. Mex., Rept. p. 332, 
pl. xxi. B. fig. 4. 
Head flat and elongate ; head-shields smooth ; three pairs of small 
shields, the two anterior separated by two minute azygos shields, 
between the rostral and a large azygos prefrontal, which is broader 
than long and separated from the frontal by a pair of nearly equally 
large preefrontals ; nasal separated from the rostral; two superposed 
postnasals, upper minute; three loreals, second not reaching the 
labials ; four small outer supraoculars, and an odd shield between : 
fourteen upper labials: temporal scales small. Sides of neck covered 
with small square shields. Lateral fold feeble, commencing in 
advance of the arm. Dorsal scales smooth, scarcely larger than 
ventrals, forming sixteen to eighteen longitudinal series. Ventrals 
