180 [OcTOBER, 
men silvery white, with two longitudinal blue colored blotches having twe 
oblique bars of black running across them; two small blue spots upon the under 
surface of tail. 
Dimensions. Length of head 74 lines; length of neck and body to anus 2 inches 
2h lines; of tail in the specimen examined, which appears to have been muti- 
lated and restored, 2 inches 3 lines: body 1 inch 5 lines in circumference; 
length of arm 6 lines; of fore arm 5} lines; of hand to extremity of longest 
nail 73 lines; of feet to extremity of longest toe 1 inch 2 lines; total length of 
body 5 inches 1 Hine. 
Habitat. New Mexico. 
Remarks. This animal approaches Crotaphytus, Holbrook, but the nostrils 
are superior instead of being lateral as in the latter genus. The head of Crota- 
phytus is covered with tubercles, and the occipital plate does not exist, or 1s 
small and ill-defined. ‘The forearm is also shorter and much more robust, 
and the ‘longest fingers are of nearly equal length; in Homolosaurus the 
fourth finger is considerably longer than the third. The temples are much 
less swollen than in Crotaphytus, which has but a single row of plates along the 
border of the lower jaw. ‘Fhe nostrils in Holbrookia are situated as in Homo- 
losaurus ; and the plates along the margin of both the upper and under jaw 
have the same configuration and arrangement; the occipital plate also is 
very distinct, which, as well as most of the plates upon the upper part of the 
head, is smooth; a considerable number of granulations, however, is observed 
above the supraciliary ridge at its anterior and posterior part, chiefly in the 
former position; but in Holbrookia there are no external ears, the ear lying im- 
mediately beneath the skin, which covers it. Both Holbrookia and Crotaphytus 
have femoral pores, but no anal ones, of which also Crotaphytus is destitute. 
Croratus LEconTEI. 
Sp. Char. Head subquadrangular, broader behind than in front, much flattened 
above; a few small plates in front; the rest of the upper surface of the head 
except over the orbit, covered with scales; a series of about thirty subquad- 
rate brownish blotches along the back, and ten or twelve transverse bands of 
the same color; brownish bands upon the tail; subquadrate blotches along the 
back, margined with light yellow; ground color lght yellow or straw-color ; 
scales strongly carinated ; abdominal scuta 174; sub caudal 27. 
Dimensions. Length of head 14 lines; greatest breadth 11 lines; length of 
body 2 ft. 2 in. 9 lines; length of tail, exclusive of rattles, 2 inches 6 lines; 
total length 2 ft. 6 inches 5 lines. 
Habitat. Cross Timbers. 
Remarks. My friend Dr. Le Conte informs me that he found near the 
Colorado, about seven hundred miles from the last mentioned locality, a species 
of Crotalus which was very abundant in that region, over four feet in length, 
and which appears to be the same as the one above described. He took the 
following notes of it upon the spot: ‘‘ Crotalus—cinereous ; back with a series 
of subrhomboidal spots margined with dark brown, and exterior to this a line 
of white scales; sides with a few darker cinereous spots; beneath pale ochra- 
ceous; neck and under part of head white; tail white, with four black rings,* 
becoming irregular beneath. Length 4% feet ; greatest circumference 5} inches ; 
185 transverse scales beneath the body, 28 caudal; fourteen scales in the ob- 
lique rows from spine to side in middle and on neck; nine posteriorly and on 
tail. Colorado, March, 1851.”? The dorsal spots become indistinct behind. 
Sandy deserts. 
* In a. young specimen brought by Dr. Woodhouse these four black rings 
are very distinct. 
