150 BULLETIN 17 5, UNITED STATES NATIONAL MUSEUM 



similar form and color. It has on each head the two sets of occipital plates, which 

 help to distinguish its species, and one set of three of nearly equal size, in a row 

 between the eyes. There are two additional dorsal spots on each neck above the 

 point of division. From the point where the crotch formed by the two necks 

 begins, to the tip of each snout, is about an inch and a half. The two heads and 

 necks are entirely separated for nearly an inch. Both heads and necks appear 

 perfect and entirely symmetrical in every way. Each head has two eyes, equally 

 large and full. It can shoot out each forked tongue together or one by one. The 

 two perfect mouths open into one throat. Each neck is equally flexible and the 

 movement of each head is perfectly natural and easy. The two heads can be 

 placed closely side by side, or one above the other and even crossed or spread 

 widely apart at will. . . . 



Each seems to have equal power, and to be alike subject to separate control 

 and motion. It eats and drinks equally well with either mouth. . . . 



Of the same specimen Johnson says: "The angle presented by the 

 frontal planes of the two heads is about 115°, that between the 



10 19 22 16 79 4 31 7 13 16 



S2 

 30 

 28 

 26 

 24 

 22 

 18 

 16 

 14 

 12 



8 9 10 11 12 13 



Region 1 2 3 4 5 6 



No. 

 Figure 71.— Qeograpbic variation in number of dorsal spots on the tail in Pituophis catenifer catenifer. 



sagittal planes about 35°. A ventral fold of skin which extends 

 forward from the point of division in the plane of the gastrosteges is 

 present. ..." 



A specimen from Pescadero, San Mateo County, Calif. (M.V.Z. 

 No. 8291), is a partial albino. Of this specimen Storer (1916, p. 74) 

 says: 



The specimen under discussion was captured in a dormant state at Pesca- 

 dero. . . . early in November, 1913, on black adobe soil where gopher snakes 

 were said to be fairly common. . . . 



The coloration of a typical gopher snake seems to be made up of three distinct 

 materials; a yellow deposit found generally distributed in the scales of the body 

 and forming the ground color, and two darker pigments, a red and a black, 

 occurring locally and forming the contrasted part of the color pattern. The 

 yellow pigment is present in the scales of the albino specimen as is also (in part 

 at least) the red, but the black is entirely lacking. Upon the anterior portion of 

 the body, where ordinarily the black and red together form brown spots only the 



