B A S C A N I X V E T U S T U S. 127 



between them. Scales smooth, disposed upon seventeen longitu- 

 dinal series. Preanal scutella subdivided. Subcaudal scutellae 

 disposed upon a double series. Adults unicolor ; young blotched. 



SYN. Bascanion, B. & G. Catal. N. Amer. Kept. I, 1853, 93. 



OBSERV. The head is elongated, narrow, and deep; the eyes very 

 large, and the vertex plate elongated and narrow also. The upper 

 anteorbital is much larger than the lower one, which is situated in a 

 notch between two labials. The fourth upper labial is produced 

 behind the eye to meet the lower postorbital. The abdominal scu- 

 tellae are from one hundred and seventy to two hundred in number, 

 the preanal being divided; and ninety to one hundred and ten sub- 

 caudal ones, all of which are divided, or else disposed upon a double 

 series. 



The teeth, as far as our observations go upon the species described 

 below, are pretty nearly equal in development upon the palate as well 

 as upon the jaws ; the premaxillary teeth being wanting. 



BASCANION VETUSTUS, B. & G. 

 (Plate VIII, figs. 12-19.) 



CHAR. SPEC. Capitis longitudine, trans scutos supraoculares, dimi- 

 diam intervaUi inter apicem rostri et extremitatem posteriorem scu~ 

 torum occipitalium, adaequante. Inferiore postorbitali scuto in angido 

 inter quartam et quintain labialem sito. Colore supra fusco-olivaceo, 

 infra paUeo-viride. 



SPEC. CHAR. Width of the head, across supraoculary plates, equal to 

 half the distance between apex of rostrum and posterior extremity 

 of occipital plates. Inferior postorbital in a notch, between the 

 fourth and fifth labials. Olive-brown above ; pale-green beneath. 



SYN. Bascanion vefustus, B. & G. Catal. N. Amer. Kept. I, 1853, 97. 



DESCR. The head is declivous upon the frontal region. The snout 

 is rounded, protruding considerably beyond the lower jaw. The 

 rostral plate is pyramidal and well developed ; the prefrontal plates 



