A POPULAR TREATISE ON THE COMMON INDIAN SNAKES. 71 



One deeply grooved, and forming the anterior boundary of the 

 loreal pit. Prceoculars. — Three, the two lowest diverging forwards, 

 and forming the upper and lower boundaries of the loreal pit. Post- 

 oculars. — Usually two (sometimes three), the lower larger, and some- 

 what crescentic. Temporals. — Two, the lower very large and in 

 contact with the 3rd, 4th and 5th supralabials normally (where the 

 supralabials are 8, it touches the 4th, 5th and 6th). Supralabials. — 

 Usually 7, the 2nd touching the eye (sometimes 8 with the 3rd touch- 

 ing the eye) ; the penultimate a very large and high shield. Infra- 

 labials. — Four, the 4th largest, and in contact with 3 or 4 scales behind. 

 Sublinguals. — -A single pair. Costals. — Two headslengths behind 

 head, 21 usually (rarely 23), midbody 21 (rarely 23), two headslengths 

 before the anus 17 ; all the rows strongly keeled except the last for a 

 variable distance anteriorly ; apical facets present in pairs. Ventrals. — 

 144 to 166. Anal. — Entire. Subcaudals. — 34 to 52, divided. 



Abnormalities.— Small scales are often intercalated between the 

 head shields. Rarely some of the anterior subcaudals are entire. I 

 have never seen a specimen with the scale rows 23 in midbody, but 

 Boulenger mentions such. 



Colour. — Very variable. Specimens occur of a nearly uniform 

 light brown, of various tints to blackish-brown. Usually the snake 

 is more or less conspicuously marked with a coarse mottling or 

 blotching, darker than the ground colour, and irregularly distributed. 

 Sometimes more or less obvious short crossbars are apparent, and 

 very frequently a light vertebral line bordered with dark zigzag or 

 sinuous stripes laterally. The flanks are beautifully dappled with 

 various shades of dark brown, and there are often some white mot- 

 tlings at the side of the neck. The head is often darker than the back, 

 and shows dark marks on the enlarged shields. A conspicuous 

 oblique dark streak bordered with white, runs from the eye to the 

 gape. The lips are enamel-white or pale pink, and so is the chin and 

 throat, and many of the labial sutures pigmented. The underparts 

 are very finely powdered with various tones of brown, sepia, rufous, 

 plumbeous or dirty white. The tail is usually reddish towards the tip. 

 Dentition and jaws — Maxilla. — Upper half hollowed out into a 

 cup, the external and posterior walls of which are deficient. This cup to 

 which the prefrontal bone provides a roof, forms a spherical cham- 

 ber — the loreal pit. Below the bone supports two canaliculate fangs. 



