4 
Reptiles of Massachusetts. 17 
back of the head, thirty-four inches; greatest depth 
fourteen inches. The body is covered above, by 
a dark brown shield, fifty-seven inches in length, of 
a firm leathery texture, which is divided into fur- 
rows by seven longitudinal elevated ridges ; all these 
ridges are noduled, resembling the vertebral column ; 
the dorsal ridge runs the whole length of the shell ; 
those on the side, next the dorsum, commence one 
inch and a half further forwards than the dorsal 
ridge, and within sixteen inches of the posterior 
extremity of the shell curve upwards towards the 
dorsal ridge, but are not so perceptible after curving, 
and reach the upper ridge, six inches anterior to the 
extremity of the shell. ‘The second lateral ridge 
commences about seven inches back of the preced- 
ing, and, at the posterior extremity, curves up like 
that; the abdominal margin makes the third lateral 
ridge. The posterior extremity of the shell is trun- 
cated, and is two and a half inches wide. 
Length of the head and neck, sixteen inches; of 
the head, nine and a half inches; width of the head 
nine inches; width of the neck, thirteen inches. 
Diameter of the eye, large. Nostrils just back of 
the tip of the snout. A large notch in the middle 
of the upper jaw, which receives the projections of 
the lower jaw, when the mouth is closed; on the 
sides of this median emargination of the upper jaw 
are two others, one on each side. Upon the mid- 
dle and posterior portion of the roof of the mouth, 
strong spinous processes. 
A portion of the «esophagus of this specimen 
belongs to the cabinet of the Boston Society of 
VOL. III.—NO. III. 3 
