Hurter — Herpetology of Missouri. 131 



Genus sceloporus. 



Head short, convex above. Upper head scales enlarged, occipital 

 very large. Nostrils near the margin of the snout, opening in a single 

 plate. A short fold on each side of the neck. The dorsal scales are 

 large, nearly equal sized, mucronate and strongly imbricate. The ear- 

 opening is large with a well developed anterior denticulation. The 

 labials are juxtaposed. The scales of the tail carinated; those of the 

 belly smooth. Femoral pores numerous. Digits with keeled lamellae 

 inferiorly. 



37. Sceloporus undulatus Bosc. Fence Lizard. Alli- 

 gator Lizard. 



Laceria undulata, Stellio undulatus, Agama undulata, Lacerta fasciata, 

 Lacerta hyacinthina, Uromastix undulatus, Tropidolepis undulatus, 

 Sceloporus longipes. 



Description. — Cephalic plates smooth or lengthwise rugose, especially 

 anteriorly, and laterally. Supraorbital region with one crescentic se- 

 ries of five or six large, transverse plates, embracing a short series of 

 three or four additional outer and inner series of smaller plates in its 

 concavity. Back of head with three plates. The middle or occipital 

 larger than the outer ones, the parietals; the former with a central 

 transluscent spot. Two frontal plates. A single nasal plate with the 

 nostril opening in its posterior part. 



Anterior border of ear-opening denticulated with three or more 

 scales. Three rows of small supralabials. On the side of the neck, be- 

 hind the ear is a fold of skin overlapping a vertical impression, which 

 is lined with minute scales. Scales above, large, sharply carinate and 

 mucronate, many of them with notches on each side of the apex. About 

 forty-five scales in a row from the occipital to a point opposite the vent. 

 Lateral scales smaller than dorsals. The belly scales smooth and 

 strongly emarginated. Femoral pores about fourteen. All the scales on 

 the tail strongly carinated and verticillated. A curved linear impres- 

 sion behind the vent. Males with enlarged post anal scales. 



Color. — Color above grayish brown, with a series of transverse un- 

 dulating black bars on each side of the back. Tail and legs above 

 barred with black. All the bars bordered posteriorly with pale. A 

 narrow black line extends from the eye backwards over the ear and 

 fore leg, and may terminate behind the latter or pass into a brown 

 band which continues along the side of the abdomen. This last is often 

 obscure or wanting. A narrow black line crosses the head from one 

 superciliary ridge to the other. Color beneath grayish white or bluish; 

 in females and young with no, or few, green or blue scales on the throat, 

 and with tbe throat, sides, and ventral surfaces of the femora speckled 

 with black, generally with a short, dark median band before the vent; 



