104 ON TEXAN REPTILES. 



and subcaudals being bifid, number 142 -f- 75, 146 + 78, 

 143 + 65, 148 + 71, 151 -f 72, 148 + 70, 150 + 68, 

 150 -f- 74, 144 + 77, and 147 + 76. Commonly there 

 are eight labials and ten infralabials ; the latter vary from 

 ten to twelve. One specimen has two anteorbitals on one 

 side. Another has two postorbitals on one side instead 

 of the usual three. Several have the scales of chin, snout 

 and lips roughened with small tubercles or papillae. The 

 dorsal blotches vary from 31 to 36, and the caudal from 

 19 to 23. On the large ones the color of the back becomes 

 nearly uniform dark brown. Small ones have a lighter 

 ground color, blotches more distinct, and the two parietal 

 yellow spots usually present. The tendency to form trans- 

 verse bands is not so evident in this species as in its nearest 

 ally T. sipedon. Beneath the anterior margin of each 

 scute, toward the sides, there are crescent-shaped spots 

 of dark color ; on some of the older ones these spots have 

 widened and lengthened until nearly the whole scute is 

 covered ; on other individuals these spots are nearly obso- 

 lete. A frequent variation in species having the bifid anal 

 is to be seen in several of these specimens. In the -anal 

 scute the dividing line is oblique, and extends back and 

 toward the right side, thus making the left portion the 

 larger. It is in front of this, the larger half, that a small 

 supplemental or half-scute appears. Two of the ten before 

 us have a half scute in front of the left half of the anal, 

 and a third has a smaller piece which does not quite reach 

 from the median line to the lateral rows. 



This is the species named Nerodia Woodhousii by Baird 

 and Girard, 1853. Hallo well's name was applied in 

 1852. 



THAMNOPHIS SIKTALIS Linn. ; Garm. 



Labials 7, infralabials 10, 1 anteorbital, postorbitals 3, 

 and rows 19 in each of the four specimens. The veutrals 



