NATURAL SCIENCES OF PHILADELPHIA. 495 



posterior elongate, its angle directed between the third and fourth (distinct) 

 upper labials. Of these there are seven, excluding two anterior, whose su- 

 tures are more or less obliterated. Lateral borders of frontal parallel ; the 

 posterior doubly sigmoid, medially in contact with the cuneiform interpari- 

 etal, exteriorly with the small froutoparietals. Parietals small, longer than 

 broad ; a transverse postparietal. Six inferior labials ; a large transverse 

 symphyseal ;j seven inferior and five infralabials on each side. Tympanic 

 orifice small, not lobate. Three rows of hexagonal preanal plates, the mar- 

 ginal longer than broad. Scales small, in forty-four longitudinal rows, those 

 of the sides arranged vertically and horizontally. Anterior extremity con- 

 sisting of brachium and anti-brachium, as long as the commissure of the mouth. 

 It is terminated on its inner face by a tubercle. Posterior extremity as long 

 as the distance from the rictus to the axilla, consisting of femur, tibia and 

 tarsus. Sole tuberculous, with two callosities, that on its external border 

 much the larger ; a tubercle-like spur on its inner. Tail very elongate. 

 Length of head and body to vent 3 inches 8 Hues ; muzzle to auricular orifice 

 8 lines ; anterior extremity 6 lines ; posterior 9 lines ; tail ? 



Color above light brown, with numerous small dark brown spots on the 

 dorsal region. Sides dark brown, darker anteriorly, where a bandlike arrange- 

 ment is assumed as far as the orbit. From the auricular opening posteriorly, 

 this is crossed by numerous blackish brown, vertical bars, with irregular light 

 posterior borders. Mentum whitish ; abdomen yellowish. 



Specimen No. 1502, Mus. Compar. Zool., Cambridge, Mass., brought from 

 near Jeremie, St. Domingo, by Dr. D. F. Weinland. 



Centropyx, Spix. 



Two species of this genus are described by Dumeril and Bibron, while Gray 

 and Wiegmann enumerate three. A fourth is here added. Anal spurs exist 

 in C. calcaratus, C. decodon and C. striatus (Wiegmann). I 

 have not seen the male C. intermedius. 



C. calcaratus, Spix. 



Intermaxillary teeth twelve, the six median smaller. Posterior cephalic 

 plates extending over the whole breadth of the head. Dorsal scales small, 

 keeled, in about forty longitudinal series. Scales of the gular fold not ex- 

 tending beyond its border. Abdominal scales in fourteen longitudinal rows. 

 Preanal scales smooth. Femoral pores twenty. 



Above olive green, with a light median dorsal line and two lateral, one ex- 

 tending from each temple to the corresponding groin. Interval between these 

 bands marked with a series of black spots. Tail and extremities spotted ; 

 posterior femoral surface marked with a black line, bordered with white. 

 Beneath white, shaded with bluish green. 



Habitat. Brazil, Guiana. 



C. decodon, Cope. 



Intermaxillary teeth ten, one on each side of the median pair, smaller. 

 Posterior cephalic plates narrower than the width of the head. Dorsal 

 scales large, in fourteen longitudinal series, becoming smaller upon the nape. 

 Scales of the gular fold acute, produced, forming a serrate border. Abdomi- 

 nal scales in fourteen longitudinal rows ; preanals smooth. Femoral pores 

 seven or eight. 



Above olive green, with short, irregular, subtransverse, black, pale-bor- 

 dered spots on the median and posterior regions, and the base of the tail. 

 A pale band extends from the temple to the crulal region ; bordered above 

 anteriorly with a black band; beneath, from the axillary region posteriorly, 

 with spots of the same color. A second pale line extends from the tympanic 



1861.] 



