81 



Genus BASCANION, B. .t G. 



Ba^canion, Baird iiiul Girard, 1853, 6, 93. Ba.icanii(m, Cope, 1875, 

 1^, 40. 



Size large, form elongated ; head distinct from the body ; narrow and 

 with sides perpendicular ; tail long. Crown-shields 9. Vertical rather 

 long and narrow. Two pairs of frontals. Loi'al present. Anteorbitals 

 2. Postorbitals 2. Nasals 2, with nostril between. Dorsal scales 

 smooth; arranged in 15 or 17 rows. Ventral plates 170 to 210; sub- 

 caudals 80 to 150. Anal plate divided. Pairs of subcaudals seldom 

 fewer than one-half the number of ventral plates. , 



Bascanion constrictor, (Linn.). 

 Black-snake. Black-racer. Blue-racer. 



Colur>er constrictor, Linnseus, 1758, 6'4, ed. x, 216 ; Holbrook, 1842^ 

 dJ/., iii, 55, pi. 11 ; Garman, 1883, 13, 41, pi. iv, fig. 3. Bascanion 

 constrictor, Baird and Girard, 1853, 6, 93. 



A long, slender snake, with a distinct head and a slender, whip-like 

 tail, w^hich constitutes about one-fourth the entire length. Head long, 

 pointed, high ; crown flat, and with the face bent down in front of the 

 eyes. Eye in a groove which runs forward to the nostril. Snout 

 pointed and rather projecting. Rostral high. Upper anteorbital large, 

 the lower very small. Upper labials 7 or 8, the large eye over the third 

 and fourth. Lower labials 8 to 10, sixth very large. Rows of dorsal 

 scales in 17 (rarely 15 or 19) rows; the scales very smooth, the median 

 narrow, the outer broad. Ventral plates 171 to 190; subcaudals 80 to 

 110. 



The color of the adults is uniform above, but varies according to age 

 and varieties from lustrous pitch-black to lead color and yellowish olive. 

 Length 6 feet or more. In its varieties or sub-species this species has a 

 range from the Atlantic to the Pacific and south to Mexico. 



Variety constrictor. 



Lustrous pitch-black above, varying to lead color. Below, the color is 

 greenish- white or slate color, with the middle line paler. There is more 

 or less white on the chin and the lower jaw. Upper labials with some 

 vhite. Specimens from the prairies of the West and Southwest are of 

 an olive-green color, and such shade into the variety flaviventris. 



The colors of the young Black-snake are so different from those of the 

 adult that one would hardly suspect it to be the same species. Instead 

 of being of a uniform color above, they are much blotched and spotted'. 

 There is a series of reddish-brown blotches with black borders along the 

 middle of the back, but disappearing on the tail. The blotches are 

 about three scales long, and reach down to about the fourth row of scales 



