CKOCODILIANS, LIZAKDS, AND SNAKES. 343 



aiul to the scaimlar collar loiiud oii all three species. Sceloporns (lu<ienii 

 is distinguished by the characters given above and principally by the 

 small dorsal scales, which are wide, obtuse, without serrations, and 

 with the keel not terminating in a point. It is most nearly allied to 

 the Sceloporus oraatns Baird, with which it agrees in the form of the 

 scales and in the coloration, but the scales in the former appear to be 

 suKillei and the blue of the belly lacks the bn id black border. 



Sceloporiis diigesii Jlovuurt. 



Ciltillojllll) 



No. 



98«6 

 0893 

 9001 

 990.') 



Number 



of apeci- 



moiKs. 



Locality . 



iBorder.s of States of Giian;i.jiiiilo and Miclioa- '\ , |» _^.^ 

 ( can, Mexico. 7 "gcs. 



SCELOPORUS PYRRHOCEPHALUS Cope. '' 



ScelojwfUK purrliocephalus Cori:, Proc. Acad. Ntit. Sci. I'hila., 1864, p. 177; Troc. 

 Am. Phil. Soc, XXII, 1885, p. 394. — Boulengeii, Cat. Liz. Brit. Mus., 2(1 

 ed., II, 1885, p. 235. 



Dorsal scales much larger than ventral, strongly keeled, uniuiucro- 

 nate, in about twenty-live transverse obliciue series from nape to crural 

 region. Lateral scales larger than abdominal ; of the latter, a portion 

 only slightly euiarginate. Scales from ear to shoulder squamous; those 

 of ear fringe a little larger thaii those anterior to them. Tail much 

 compressed. Femoral pores twelve. Supraorbitals live, transverse, in 

 immediate contact with narrow marginals, not touching superciliaries. 

 Pronto parietal narrow; frontal broader than long, not divided. Parie- 

 tals exceedingly small; interparietal large, much broader than long. 

 Frontonasals, two each side, broader than long; jiosterior in contact; 

 anterior embracing broad hexagonal iuternasal. Infralabials small, 

 except the anterior pair, which are large and extensively in contact. 

 Prom end of nuiz/le to ear, 12.5 mm.; ear to vent, 11) mm.; length of 

 anterior limb, 12.5 mm. ; of hinder limb, 23 mm ; of hinder foot, 14.5 mm. 



(Ireenish brown, with a broad black band from the scapular region 

 to the groin, light bordered above. Below yellowish, sides bluish ash 

 to near the median line, ou each side of which is a series of from seven 

 to nine transverse blue bars. Upper labial and gular region striped 

 with a series of black or bluish lines, which converge posteriorly on a 

 paler or deeper yellow ground. Top of the head bright chestnut-red; 

 the (bntanelle white or pink, surrounded by a pale area. In females 

 the head is brown above, excei)t the parietal spot; the lateral stripe is 

 obsolete, and the blue marks of the sides of the abdomen are replaced 

 by brown. 



This handsomely miirked species is one of those which inhabits both 

 the Tierra Caliente and the i>lateau of the western part of Mexico. It 



