342 PROCEEDINGS OF THE NATIONAL MUSEUM vol. los 



habitat and geographic distribution. Moreover, both species are 

 relatively rare in those areas where their ranges approach one another. 

 It is possible that C. velox is a direct derivative of C. inornatus. As 

 far as we are aware, no definitely identified specimens of velox have 

 been reported from Santa Fe, but the species has been collected in 

 New Mexico at Taos, Taos County; 5 miles south of YoungsvUle, 

 Rio Arriba County, a site some 50 miles northwest of Santa Fe; and 

 2 miles west of Sands, San Miguel County, some 30 miles southeast 

 of Santa Fe. That the species wUl ultimately be collected near 

 Santa Fe seems inevitable, for it is a member of similar pinyon- 

 juniper communities not far distant and has been taken both to the 

 north and south of this locality. 



C. velox dift'ers from perplexus in that the median stripe if present 

 and complete is indistinct, lighter in color and narrower than the 

 paravertebral light stripes and never undulant; the paravertebral 

 light stripes are separated by about eight scales; there are no spots in 

 the dark fields; the post-antebrachial scales are larger than those of 

 perplexus but not as large as those of ino?matus; the intermandibular 

 scales are larger and abruptly demarked from the anterior gular scales 

 along a transverse line (in an occasional specimen this is not marked) ; 

 the largest scales on the gular fold are usually larger but often equal 

 in size to the largest median intermandibular scales; the gular fold is 

 unnotched and the enlarged scales along it are not interrupted medially 

 by a patch of smaller scales; the temporal scales are slightly larger; 

 the third supraoculars are in broad contact with the frontoparietals. 



C. neomexicanus has not yet been taken as near to Santa Fe as has 

 velox. The nearest known locality for neomexicanus is 6 miles south 

 of Bernalillo, Sandoval County, near the Rio Grande and about 50 

 mUes southwest of Santa Fe. HoAvever, this locality more closely 

 approaches the probable type locality for perplexus than does any 

 in the presently known distribution of velox. 



C. neomexicanus differs from perplexus in only a few characters, 

 but these differences are for the most part concerned with variable 

 characters and fall within the range of variation described by Lowe 

 and Zweifel (1952). The chief and most important difference lies in 

 the fact that in most specimens of neomexicanus the fourth, third, 

 and often the second supraoculars are separated from the median 

 head plates by small scales (circumorbitals). In the type of perp)lcxus 

 only the fourth supraocular and three-fourths of the third are so 

 bordered. Another marked difference is in size. Of the 48 specimens 

 available to Lowe and Zweifel (1952), all from Socorro County, 

 N. Mex., the largest is a female measuring 76.4 mm. from snout to 

 vent. The type of perplexus, also a female, measures 86 mm. In all 

 other characters the two forms are strikingly similar. 



