Johnson — Axial Bifurcation in Snakes. 527 



Case IX. This is the young Bascanium constrictor Linn. 

 [Plate XXXVI, Fig. 9] described by Wyman in 1863. It was 

 obtained from the Warren Museum of the Harvard Medical Col- 

 lege. When the necks are as long as in this specimen, it is 

 impossible to determine the angle of the frontal planes. 

 However, as the snake is now, this angle is 90°. The heads 

 and necks are nearly equal. From the point of external divi- 

 sion to the point of division of the vertebral column, the dor- 

 sal blotches are in two rows. 



Case X. This is the snake in the United States Xational 

 Museum bearing the catalogue nimiber 25398 [Plate XXXVII, 

 Figs. 10 and 10a.] It was collected by Miss M. Desha; the 

 locality is not given. It belongs to the genus Pityopliis, but its 

 specific position in this difficult genus is less plain. If, how- 

 ever, the species Pitypliis sayi Schlegel be made to include 

 Pityophis hellona Bd. and Gird, following Cope, it may be 

 called Pityophis sayi, since it seems intermediate between these 

 two forms. This specimen is remarkable for the extreme length 

 of the anterior doubled portion, which is much longer than in 

 any case ever described, with the exception of that of Redi. 

 The skiagraph reveals the division of the vertebral column 

 very much farther back than that of the bodies proper, although 

 the color markings show irregularities over the portion un- 

 derlaid by the two vertebral columns. 



Case XL This small snake embryo [Plate XXXVIII, Fig. 

 11] has been so bady dessicated that a determination of its spe- 

 cies is impossible. Together with cases XII and XIII it was 

 purchased from a dealer, Mr. X. L. Wilson of 170 Tremont St., 

 Boston, Mass., who was unable to furnish data concerning any 

 of his specim.ens. The point of division is posterior to the 

 eyes. The angle of the sagittal planes is apr)roximately 80°, 

 and there is no appreciable angle of the frontal planes. 



Case XII. This is an embrvo of Eutainia sirtalis Linn, 

 still without color [Plate XXXVIII, Fig. 12.] It is remark- 

 able for the considerable inequality in the length of the two 

 necks and the deficiencies in structure. The rii^ht head on the 

 shorter neck is singularly deficient. The lower jaw is repre- 

 sented by a mere stump and the dorso-ventral thickness of the 



