164 OP HID I A. 



inclosed by the first pair of lower labials, which are narrow and lanceo* 

 lated. The lower labials themselves are eight in number; the second is 

 the smallest; they increase in size to the fifth, which is the largest, hence 

 diminishing posteriorly ; the fourth, however, is nearly as large as the 

 fifth. The mental shields are slender ; the anterior pair, acute upon 

 both extremities, are a little shorter than the posterior pair, which are 

 rounded posteriorly, and diverging in order to admit a few of the 

 small and numerous scale-like shields which cover the throat. 



The neck and body are slender and subcircular. The tail is very 

 much tapering towards a filiform point. The scales are subrhomboid, 

 slightly carinated on the back, disposed upon seventeen longitudinal 

 series, eight of which may be observed upon the base of the tail. The 

 series adjoining the abdominal scutellae is smooth, and much larger 

 than the others. The abdominal scutellae are rather narrow, two 

 hundred in number, the preanal one being subdivided ; the subcaudal 

 scutellae are disposed upon a double series, about one hundred and 

 fifteen in number. 



The total length of the specimen described is nine and a half inches, 

 giving two and a half inches to the tail. 



The ground color is bluish-grey above. A double series of roundish 

 deep-brown spots, with a marginal black fillet, may be observed along 

 the dorsal region, contiguous upon their inner margins, with a tendency 

 now and then to alternate ; towards the posterior portion of the body, 

 they emerge into a uniform band, which may be traced tapering down 

 the tail, still margined with a black fillet. On each side of the body is 

 a series of much smaller spots, sometimes opposite to one another, at 

 others, alternating with the dorsal series, and anteriorly with a vitta 

 of the same hue, which exists along the temporal region, across the 

 eye to the nostril. The upper surface of the head being merely spotted. 

 The scales of the two external rows are light brown upon their middle. 

 The extremities of the abdominal scutellae are spotted, which spots 

 constitute an abdominal series on each side. The inferior region, 

 otherwise, is of a uniform yellowish hue. 



Log. — A small specimen was obtained at San Lorenzo, coast of 

 Peru. 



