317 
The general arrangement of the shields of the head being the same 
as in Mabouia agilis, it does not appear necessary to give a detailed 
description of them. The present species is very similar to the latter, 
but distinguished by a considerably shorter snout. The large scales 
on the back and the large anal shields are sufficient characters to 
distinguish it from M. lacepedii, &c. 
OPHIDIA. 
LEPTODEIRA DISCOLOR. 
Diagnosis.—Anal bifid ; scales in nineteen rows. Posterior maxil- 
lary tooth longest and strongest, in a continuous series with the other 
teeth, not grooved. Dirty-white, with numerous black cross-bands 
extending on to the ventral plates ; belly uniform whitish. 
Hab. Oaxaca (Mexico). 
Description.—The head is rather broad and depressed, the snout 
rounded ; the eye is of moderate size, its vertical diameter being 
about one-third the width between the eyes ; the trunk is rounded, 
and, like the tail, somewhat slender. The rostral shield reaches 
just to the upper surface of the snout ; the frontals are nearly square : 
the anterior pair are one-third the size of the posterior, which are 
slightly bent downwards to the side of the head ; the vertical is pen- 
tagonal, longer than broad ; the occipitals rounded posteriorly. 
Nostril situated between two nasals; loreal quadrangular; one an- 
terior and two posterior oculars ; seven or eight upper labial shields, 
the third and fourth or the fourth and fifth entering the orbit. There 
is one elongate temporal shield in contact with both the oculars ; the 
other temporals, five in number, are scale-like. The medial lower 
labial is triangular and rather small; nine lower labials, the first of 
which is in contact with its fellow behind the median shield. There 
are two pairs of chin-shields, of nearly equal size. The scales are in 
nineteen rows, smooth, rhombic, those of the sides similar to those 
on the back. The number of the ventral plates varies between 182 
and 179, that of the caudal between 88 and 87. 
The ground-colour of the upper parts is dirty-white: the upper 
part of the head is brown ; there is a whitish collar behind the occi- 
pitals. Fifty-one or fifty-four black bands cross the trunk and ex- 
tend on to the edge of the belly ; they are broader than the inter- 
spaces between, and become interrupted and spot-like on the tail. 
All the lower parts are uniform whitish. 
in. lin 
Sa UMC rN i a Al «Al 
Length, of the Heady cp. 0. «sie eins w «das sR 4 
Greatest width of the head........ si O,. be 
Length. of te tape oa << 2j<;0, Seem s,« ns 14 6 
ME Bao ha hia a 5 aes, 0"s 6 0 
This species might be easily taken for a variety of Leptodeira an- 
nulata or Leptodeira torquata*, exhibiting nearly the same phy- 
siognomy, and externally differing only in its more slender body, 
* Ann. & Mag. Nat. Hist. March 1860, p.169, pl. x. fig. A. 
