1877.] 93 |Cope. 
degree than its nearest ally the O. plumbeus. The form of the rostral plate, 
peculiar relations of the loreal and preoculars, with the single temporal in 
contact with the postoculars, short tail, and cclor serve to distinguish it 
from that species. 
From the same locality as the last. With them were collected the fol- 
lowing species. 
Hyla vauterii Bibr. Dryophylax oifersti Licht. 
Aporophis anomalus Gthr. (L. ruti- Opheomorphus merremii Neuw. 
lus Cope). Thamnodynastes nattererii Mik. 
Dryophylax schottit Fitz. Herpetodryas carinatus L. 
CNEMIDOPHORUS MICROLEPIDOPUS Cope. 
A species distinguished by the small size of the scales on the brachium 
and thigh. 
A few rows of large scales on the collar; the edge with much smaller 
scales ; two preoculars and a frenoécular ; three supraorbitals ; larger gu- 
lar scales few and in the centre of the throat ; postbrachials numerous, 
small; brachials in 3, femorals in 14 rows; olive, with eight indistinct pale 
bands, black between the two inferior. 
There are several flat small scuta behind the parietals and interparietals. 
There are a few points of coloration to be observed in describing this 
lizard. There are four yellow spots at the corners of an imayinary square 
which encloses the tympanic disc. There is another between the antero- 
superior of these and the orbit, and another below the posterior part of the 
eye. The inferior yellow line is continued on the tail. 
About the size of C. sexlineatus ; as the median dorsa] lines are faint 
in the single specimen is not probably young. 
West Tehuantepec, Sumichrast. 
CNEMIDOPHORUS UNICOLOR Cope. 
A small species distinguished by the absence of coloration marks. 
A few rows of large scales on the collar; the edge with much smaller 
scales ; two preoculars and a frenoécular ; three supraorbitals ; larger gu- 
lar scales few and in the centre of the throat ; postbrachials larger, above 
point joining brachials which are in 5 rows; femorals in 10; olive brown 
with one pale lateral line ; four pale spots below and behind eye. 
There are four yellow spots round the tympanic membrane, one below 
the eye, and one between the latter and the nearest one of the former, as 
in C. microlepidopus. The dorsal scales are minutely roughened. It is in 
general characters allied to the C. ¢nornatus Baird from Northern Mexico. 
The latter differs in the presence of four supraorbital plates, smaller collar 
scales, and coarser and rougher dorsal scales. 
West Tehuantepec, Sumichrast. 
CNEMIDOPHORUS IMMUTABILIS Cope. 
This species attains to the largest size known in the genus, without losing 
its striped coloration, as do the other large forms. 
