LIZARD CNEAIIDOPHORUS PERPLEXUS — jVIASLIN, ET AL. 343 



The color patterns and the arrangement and size of the brachial, 

 antebrachial, and post-antebrachial scales are identical; neomexicanus 

 nsually has a peculiar, anteriorly directed open notch on the gular 

 fold as does perplexus; the scales of the gular fold are only moderately 

 and gradually enlarged anteriorly as they are in perplexus and their 

 maximum size is less than or equal to the largest median intermandib- 

 ular scales. The enlarged gular scales are occasionally interrupted 

 medially, as in the type of neomexicanus, by a patch of small scales. 

 This condition closely approximates the condition of the type of 

 perplexus. The iutermandibular scales are larger than the anterior 

 gular scales as they are in ])erplexus and usually are not sharply dc- 

 marked from them; however, on either side a few small scales, arranged 

 in a short transverse row, often separate the two areas laterally in 

 neomexicanus, but not medially. The arrangement and size of the 

 temporal scales are as similar in the two forms as this type of scalation 

 can be. The number of scales from the occipital region to the rump 

 in the type of perplexus is 178, this is within six scales of the average 

 given by Lowe and Zweifel (1952) for neomexicanus, namely 184.3 ± 

 1.2; and the number of circumabdominal scales exclusive of the 

 ventral plates is 73, two scales less than the mean of neomexicanus 

 which is 74.9 ±0.62. In spite of the differences in body size and the 

 extent of the anterior extension of the circumorbital semicircles we are 

 convinced at this time that neomexicanus and perplexus are one and 

 the same. 



It is appropriate to point out that this finding — tiie first proper 

 allocation of the old name Cnemidophorus perplexus to a definitely 

 known population — has been made possible through the detailed 

 study of variation by Lowe and Zweifel (1952), where for the first 

 time the body scale counts were determined and analyzed statistically 

 in a study of variation in the genus Cnemidophorus. 



The remaining specimens upon which the description of perplexus 

 was based have been examined and may be identified as follows. The 

 five specimens (USNM 3022) collected by John H. Clark in the valley 

 of the Rio San Pedro of the Rio Grande del Norte are all Cnemi- 

 dophorus sacki gularis Baird and Girard. The two specimens of USNM 

 3050, "collected" by General Churchill on the Rio Grande west of 

 San Antonio, are both Cnemidophorus inornatus Baird. The second 

 specimen, collected hy Gambel and originally bearing the same num- 

 ber as the type (USNM 3060), is now numbered USNM 30885. This 

 is also a specimen of Cnemidophorus inornatus. 



For the most part descriptions of specimens of perplexus in the 

 literature are so brief as to make identification virtually impossible. 

 Furthermore, so many lined whip tails have been confused with each 

 other that all of the earlier, more extended accounts of these forms, 



