REPTILES. 
97 
To these must be added the Agama Douglasii of Mr. Bell. Lin. Trans, xvi. t. 10. Phrynosoma 
Douglasii, which has no lateral fringe, and the back scattered with trihedral larger scales. 
Thus there are at least fire species of this genus, which are all peculiar to America. Specimens of 
three are in the collection of the British Museum. 
Leiocephalus carinatus, t. 29. f. 3. Gray in Ann. Phil, and in Griffith, Anim. 
Kingd. 42. 
Inhab. South America. — Cab. Brit. Mus. 
Coluber (natrix) subcarinata, t. 32. 
Above olive brown; sides obscurely brown spotted, beneath yellow; with a black-edged pale 
dorsal band, two half scales wide. The body fusiform ; the head rather depressed, with one tos- 
tral scale, triangular notched below. Nasal scales triangular, with nostrils pierced in their centre; 
with two triangular internasal plates, and two rather larger fronto-nasal plates; two frontal and one 
nearly equal-sided superciliary scale on each side of it, and two larger parietal plates ; one anterior 
and three posterior orbital scales on each side, with a very small triangular scale between the anterior 
one and the nasal plate. Mouth very large, gape reaching beyond the eyes. Upper lips with eight, 
and lower with ten labial scales on each side ; the first lower lateral scales on each side very long. 
Mental plates, two pairs, the hinder largest, with three or four cross series of gular scales before the 
gular plates. The dorsal scales lanceolate, keeled, in about seventeen longitudinal series; the two 
central series strongly keeled, with the keels diminishing in distinctness, and the scales increasing in 
width towards the sides, so that the scales of the series next the abdominal plates are hexagonal, as 
broad as long, nearly twice as broad as the vertebral scales, and almost smooth. The ventral 
plates about one hundred and forty, wide, regularly arched, and yellowish. Tail conical, tapering 
slender, about one fourth of the length of the body, with eight or nine series of strongly-keeled 
hexagonal scales above, and with about seventy pairs of subcaudal plates. Length of the body, 
two feet ; of the tail, seven inches. 
Inhab. common in the hedges of Xalisco, a province of Mexico. — Tradescant Lay, Esq. ; the specimen 
in the Museum of the College of Surgeons. 
This species is nearly allied to Coluber bicarinatus of Prince Maximilian of Wied, (Reise in 
Brasilien, I. 181), and the Natrix bicarinata of Wagler, (Serp. Braz. t. 7;) but the latter describes the 
tail of his snake as more than half the length of the body, and the two dorsal series of scales alone 
as keeled, and observes that the others are six-sided, with a scarcely elevated line; none of which 
characters agree with the specimen under consideration. 
O 
