| OCR Text |
Show 126 ON A NEW AFRICAN SNAKE. [Feb. 18, 5. Description of a New Snake of the Genus Psammophis, from Cape Colony. By G. A. BOULENGER, F.R.S. [Received February 17, 1902.] (Plate XII.) PSAMMOPHIS LEIGHTONI. (Plate XII.) Snout once and two thirds as long as the eye, with a shallow concavity in front of the vertex. Rostral a little broader than deep, visible from above; nostril between three shields; inter-nasals shorter than the prefrontals; frontal twice as long as broad, in the middle about two thirds the width of the supraocular, as long as its distance from the end of the snout, slightly shorter than the parietals ; loreal twice as long as deep ; a single pra?ocular, forming an extensive suture with the frontal; two postoculars ; temporals 2 -f 2 ; eight upper labials, third deeper than second and fourth, fourth and fifth entering the eye; four lower labials in contact with the anterior chin-shields, which are shorter than the posterior. Scales in 17 rows. Yentrals 156; anal divided ; subcaudals 84. Dark brown above; the middle row of scales black with yellow shafts forming an interrupted light vertebral line; a yellow lateral streak along the adjacent halves of the third and fourth rows of scales; the upper half of the fourth scale black; scales of outer row yellow in front and brown or black behind ; sides of neck with dark ocelli edged with bright yellow; head dark brown above, with a yellow line along the middle of the snout and another on each side of the frontal shield ; two pairs of yellow spots on the parietal shields; four yellow bars on each side of the head, the first on the prse-ocular, the second on the postoculars, the third extending to the upper surface of the head and nearly meeting its fellow on the occiput; rostral and labials yellow, with black spots; lower parts yellowish white, with black dots and two bluish-grey longitudinal lines which widen forwards into two bands and unite on the throat. Total length 910 m m . ; tail 270. A single specimen, from Eerste River Station, 21 miles east of Cape Town, was received by Dr. G. Leighton, of Pontrilas, Hereford, and presented by him to the British Museum. In its markings this Snake differs from all its congeners. It differs from P. sibilans in having the rostral shield broader than deep, as in P. notostictus, in which the prseocular and the anal are divided. EXPLANATION OF PLATE XII. Psammophis leightoni. Upper, lower, and side views of head and anterior part of body and upper view of middle part of body. Natural size. |
