TESTUDINIDA. 447 
Considerable portions of the carapace of this specimen are preserved; but they are in a 
fragmentary condition. The costals are crost by conspicuous ridges and grooves. 
Cope’s “No. 2,” No. 1323 of the American Museum, presents an imperfect carapace 
(plate 19, fig. 7), most of the lateral and all of the hinder border being gone. Cope states that 
the axial length was 330 mm.; but it is certain that it was in life considerably longer. Cope 
describes the carapace as being flattened, but this appearance is undoubtedly due to the bad 
state of the specimen. The front outline is truncate, with the nuchal and peripheral bones flared 
considerably upward. The sutures between the various neurals and costals are not well shown. 
The nuchal scute is said by Cope to be 4 mm. long, but this appears to be a misprint for 40 mm. 
Its width anteriorly is 17 mm.; posteriorly, 24 mm. The second and third marginal scutes are 
67 mm. wide fore and aft. The first vertebral scute is 110 mm. wide in front and 77 mm. wide 
behind. The second and the third are 110 mm. wide across the middle, and this width 1s about 
that of the costal scutes. On the hinder portion of the first vertebral scute area is a conspicuous 
boss, from which a ridge continues forward some distance. On each of the other vertebral 
606 
Fics. 604-606.—T estudo orthopygia. Carapace and dermal ossicles. 3. 
604. Patch of dermal armor near the tail, showing a bony spur. 
605. Plan of carapace, constructed from various specimens in A. M. N. H. 606. Ilium. 
areas there is a depression, horseshoe-shaped, with the opening forward. The costal bones are 
grooved and ridged parallel with the borders of the carapace. 
Cope’s “No. 3” is evidently the specimen now bearing the American Museum’s number 
1324, and furnishes the hinder half of the carapace. It is a smaller specimen than the one 
described above, the width of the carapace at the inguinal notches being only 250 mm. The 
hinder border is rounded, most of the peripherals are somewhat flared upward at the border, 
and the free edges are acute. The fifth vertebral scute is 33 mm. wide in front, 100 mm. behind 
and 62 mm. long in the midline. All of the costal scute areas and that of the fifth vertebral 
are sculptured with grooves and ridges which run parallel with the border cf the carapace. 
After a study of all the iatereds at hand the writer has concluded that the specimens 
called cyclopygia are merely the young and half-grown individuals of 7. orthopygia. The 
grooving of the carapace may be observed on some of the costals of specimens that must be 
referred to orthopygia. The width of the pectoral scutes varies in different examples and prob- 
ably becomes relatively greater in the older individuals. The same remark may be made 
regarding the notch in ‘the rear of the plastron. The anterior lip of the plastron is likewise 
variable, but within what limits it is hard to say. The usual form in the larger individuals, some 
