SCELOPORUS GRACILIS. 387 



space of which is a series of black spots. Beneath yellowish; under 

 surface of head clouded with bluish. Male provided with an elon- 

 gated blue patch on each side of the abdomen. 



SYN. Sceloporus gracilis, B. & G. in Proc. Acad. Nat. Sci. Philad. VI, 1852, 175. 



DESCR. We have before us a slender and quite graceful species, 

 the snout of which being proportionally more elongated than in any 

 of the species above referred to. The occipital plate is almost subtri- 

 angular, being acute anteriorly, and rounded off posteriorly. The 

 vertex plate, transversely subdivided through the middle of its length, 

 is quite narrow posteriorly. The postfrontals are contiguous upon a 

 greater surface than in the other species here described : hence, the 

 vertex plate is more isolated from the middle frontal. The supra~ 

 oculars are similar, in shape and development, to those of 8. occiden- 

 tal is and S. frontalis, with this difference, however, that the external 

 subcrescentic series is composed of plates a good deal larger. The 

 internal parallel series are larger also in the same proportions. 



The dorsal scales are rhomboid, slightly keeled, and their posterior 

 margin is entire, instead of being indentated laterally; they constitute 

 longitudinal and parallel series. The caudal scales are much larger 

 than the dorsal ones. On the flanks, the scales are disposed upon ver- 

 tical series, the carination becoming very obsolete, and disappearing 

 entirely along the lower portion ; on the throat, they are notched 

 upon their posterior margin, whilst on the abdomen, they are almost 

 altogether entire, a few notched ones being scattered over the sides. 

 The scales on the upper surface of the limbs are obsoletely keeled, 

 and smooth on the lower surface, except on the sole of the feet, where 

 they are conspicuously keeled ; on the posterior aspect of the thighs, 

 they are small, rounded, and smooth; on the tail, the scales are more 

 strongly carinated than elsewhere. 



The ground color above is of an olivaceous brown, and yellowish or 

 dull whitish beneath. There are two lateral, narrow, and yellow 

 streaks on each side : one extending from the orbit to the origin of 

 the tail ; the other, from the auricular aperture to the groin. The 

 dorsal region exhibits a double series of black subcrescentic spots, con- 

 vex backwards, extending from the occiput to the narrow and conical 

 portion of the tail. The intervening zone, between the lateral streaks, 

 exhibits also a series of black subcrescentic spots. The upper surface 



