138 



bonier. The second vertebral plate presents the usual hexagonal coffin-like 

 outline, but in a reversed position, its broadest part being about one-fifth of 

 ils length in advance of its back border. The third vertebral plate is oblong 

 quadrate, with the fore and lateral borders convex, and the back one nearly 



straight. 



The sutures defining the first costal plate depart from the anterior narrow 

 end and the posterior widest part of the first vertebral plate. The scute 

 impressions of the carapace are well defined by deep grooves. 



The nuchal scute impression is Hat, and widens anteriorly. The first mar- 

 ginal scute impression is wider than long. 



The first vertebral scute area is longer than broad, and is purse-like in 

 outline. 



The second vertebral scute area is also longer than broad, and is quadrate, 

 with the lateral borders nearly parallel. 



The fragment of the carapace from its front border to the back border of 

 the third vertebral plate measures 13^ inches. 



Other measurements of the carapace are as follows : 



Lines. 



Length of nuchal plate , - 50 



Breadth of nuchal plate iu front 44 



Breadth of nuchal plate where widest 60 



Length of first vertebral plate 48 



Breadth of first vertebral plate in front 9 



Breadth of first vertebral plate where widest 30 



Breadth of first vertebral plate at back border 14 



Length of second vertebral plate 27 



Breadth of second vertebral plate where widest 20 



Breadth of second vertebral plate at back border 1 16 



Length of third vertebral plate 29 



Breadth of third vertebral plate at middle , 22 



Breadth of third vertebral plate at back border _ 17 



Length of nuchal scute impression 21 



Breadth of nuchal scute impression in front 11 



Breadth of nuchal scute impression behind 



Length of first marginal scute impression 2G 



Breadth of first marginal scute impression behind 38 



Length of first vertebral scute impression * 07 



Breadth of first vertebral scute impression in front 32 



Breadth of first vertebral scute impression near middle 52 



Breadth of first vertebral scute impression at back border 43 



Length of second vertebral scute impression 58 



Breadth of second vertebral scute impression at middle 48 



The accompanying plastron measured, in its complete condition, upward 



of 2 feet in length and about 1^ feet in breadth. 



