112 



BULT.ETIN 154, UNITED STATES NATIONAL MUSEUM 



absent in the lateral fields of the yoimii' ^^^' in the lines themselves; 

 •ri'ound color of back and sides often distinctly contrasted, that 

 of the back li<:liter; sides brown, olivaceons, black, reddish or gray. 



A total of l.nT^ specimens of </ul<n/.s ha\e been examined and are 

 all found to be remarkably unifoiiu in most proportional and 

 scutellational features. A specimen from Colima, Colima, Mexico 

 (U.S.N.M. No. 58GTG), apparently is the largest one in collections. 

 It measures as follows: Body, 164 mm.; tail, 320 (regenerated); 

 total length, 484; width of head, 34; length of hind leg, 105. A 

 representative series of 350 additional specimens gives the following 

 range of variation: Body, 40-13G mm.; tail, 87-302; total length, 

 134-432; length of tail as percentage of total length, G3-T6; width 

 of head, G-24; width of head as percentage of body length. 18.8- 

 21.0); hind leg, 2G-91; length of hind leg as percentage of body 

 length, 58-78 ; supraoculars 4 in 33G specimens, 5 in 5 specimens, 4—5 

 in 8 specimens, and 4-G in 1 specimen; supraocular granules not 

 extending forward past the anterior border of the fourth supraocu- 

 lar in 42 specimens, extending to the middle of the third supraocu- 

 lar in 285 specimens, to the anterior border of the third supraocular 

 in 22 specimens, and to the anterior border of the second supraocu- 

 lar in 1 specimen. 



Variation. — Considerable geographical variation has been noted in 

 the number of femoral pores and the position of the supraocular 

 granules. In order to show this variation, a representative .series 

 from Guatemala, central INIexico, and Texas, has been studied. The 

 following table shows tliat no definitive diiference between these 

 populations exists, but that a significant evolutionary trend has 

 taken place with northward extention of the range. This trend to- 

 ward reduction botl> in the nuuil»er of femoral [)ores and in the num- 

 ber and forward extent of the supraocular granules is definitely 

 toAvard the northern subspecies, sexlineatus and 'peiylexus^ with 

 which (julai'h intergrades extensively along common boundaries. 



Table showing the geographical variation in the number of femoral pores and in the 

 on of the supraocular granules of C. sexlineatus gularis 



Locality 



Guatemala 



Central Mexico 

 Texas 



1 This refers to the forward extent of the supraocular granules and the numerals used denote the following 

 conditions: 2= extending forward to the anterior border of the second supraocular; 3= extending forward to 

 the anterior border of the third supraocular; pt. 3= extending forward to the middle of the third supraocular; 

 4= extending forward to the anterior border of the fourth supraocular. 



