Vol. X] VAN DENBURGH— VARIATION IN GOPHER-SNAKES 25 



or the presence of dark keels on the scales, especially laterally 

 and anteriorly. Along the middle of the back, from the head 

 to a point over the anus, is a series of from 37 to 55 (average 

 46) reddish-brown blotches. The brown of these blotches be- 

 comes darker and redder posteriorly. These blotches often are 

 margined with black. On the upper surface of the tail are from 

 ten to fourteen (average 12.5) dark reddish-brown blotches or 

 cross bands. On the anterior part of the body the blotches 

 tend to be more or less rounded, posteriorly they are more 

 quadrate, or are wider with concave anterior and posterior bor- 

 ders. There are two or three series of alternating, often more 

 or less confluent, dark blotches or spots on the sides. Across 

 the top of the head between the preocular plates is a narrow 

 brown band, more or less obsolete in adults. There are similar 

 bands or spots below the center of the eye and running back 

 and down from the upper postocular plate. The top of the head 

 is light brownish-yellow, speckled with black. The spaces be- 

 tween the dark dorsal blotches on the posterior part of the body 

 are light yellowish or grayish-orange, usually without dark 

 marks on the keels of the scales. The lower surfaces are yel- 

 low or yellowish-white, with irregular spots or blotches of 

 light or dark brown on the gastrosteges and urosteges. There 

 is no definite median subcaudal dark band. 



Length to anus 456 1050 "*1115 1130 1140 



Length of tail 68 154 153 183 165 



Variation. — Sixteen specimens from Arizona show the fol- 

 lowing variations : The loreals are 1-1 in all. The preoculars 

 are 1-1 in ten, or 62% ; 2-2 in five, or 31% ; and 1-2 in one, or 

 6%. The postoculars are 3-3 in six, or 37% ; 3—i in five, or 

 31% ; 4—4 in four, or 25% ; and 4-5 in one, or 6%. The tem- 

 porals are 4-4 in seven, or 47% ; 3-3 in three, or 20% ; 3-4 in 

 two, or 13% ; 4—5 in two, or 13% ; and 2-3 in one, or 7%. The 

 supralabials are 8-8 in eight, or 50% ; 8-9 in three, or 19% ; 

 9-9 in three, or 19% ; 9-10 in one, or 6% ; and 8-10 in one, or 

 6%. The infralabials are 12-12 in nine, or 60%; 13-13 in 

 three, or 20% ; 13-14 in one, or 6% ; 14—14 in one, or 6% ; and 

 1 1-1 1 in one, or 6%. The scale rows are 33 in eight, or 50% ; 

 31 in six, or 37% ; 29 in one, or 6% ; and 35 in one, or 6% ; the 

 average is 32.1 rows. The gastrosteges vary in number from 



