234 FOSSIL TURTLES OF NORTH AMERICA. 
beds of the same period in the region about Milk River, British America. As the Judith 
River beds are now known to be much lower in the geological scale than the Laramie it is 
probable that a distinct species is there included. The Arapahoe and Denver beds being prob- 
ably above the Laramie, it is not improbable that the remains reported from that horizon by 
Cope and Marsh belong to a third species of the genus. 
Leidy’s type an dicated a turtle whose carapace had a length of about 365 mm. The neural, 
regarded as the fourth, was 26 mm. long and 27 mm. adel The costal plate believed to be 
che fifth, was 28 mm. wide at the middle OF the length. It is rather strongly archt, showing that 
the shell was not deprest. This costal had a thickness of 7 mm. where it joined the neurals. 
It is crost at the proximal end by the costo-vertebral ice from which proceeds the sulcus 
that separated the third and fourth vertebral scutes. The position of the longitudinal sulcus 
indicates that the vertebrals had a width of about 65 mm. Leidy’s estimate that they were 
2 inches wide 1s too small. 
The specimens figured by Cope in his Vertebrata of the Cretaceous Formations of the West, 
plate vi, figs. 15, 16, were collected in 1873, in northeastern Colorado. No statement is made as 
to the exact locality, but they probably came from the Denver beds in the region about Bijou 
Creek. We can not be really certain that they belong to Leidy’s species. Cope’s fig. 16 
represents a posterior peripheral, apparently the ninth of the left side, with the sulcus between 
the third and fourth costals running down its anterior half. The bone is 39 mm. high, 32 mm. 
wide at the free border, and g mm. thick at the costal border. There is no pit for the rib-end. 
The bone thins to an acute free border. The upper surface is only slightly concave. The 
sculpture resembles that of the 
type of the species. A remarkable 
feature of this bone is the low 
position of the costo-marginal 
sulcus. [his runs much nearer 
the free than to the costal border. 
Fics. 292-295. —Compsemys victa. 
Fragments of shell. Xj. 
292. Portion of right costal. No. 6096 
A. M.N.H. 
293. First right peripheral. No. 1085 
A.M.N.H. 
294. Fragment of bridge peripheral. No. 
998 A. M. N. H. 
295. Portion of right hyoplastron. No. 
1o15 A. M.N.H. 
295: 
aK 
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In Gly ptops plicatulus, as is usual in turtles, it runs nearer the costal border. In the periph- 
eral here described the scute-covered surface on the inferior side of the bone extends to within 
15 mm. of the costal border. The granulation is finer than on the upper side of the bone. 
The other fragment figured by Cope furnishes little additional information. 
A right eighth costal, No. 6096 of the American Museum of Natural History, collected by 
Mr. J. C. Isaac, i in 1877, in the Laramie beds, on Lance Creek, Wyoming, was at least 40 mm. 
wide and from 5 mm. to 8 mm. thick (plate 34, fig. 3; text-fig. 292). The proximal portion and 
a part of the hinder border are broken away. On the lower surface there is the base of a 
seronely developt rib-head; but there is no ridge corresponding to the rib, nor any projecting 
distal end of the rib, such as we find in Glypiops. Near the hinder border of the bone is a sulcus, 
that separating the fourth costal scute from the fifth vertebral. On the peripheral border are 
two loops of a sulcus, one narrow, the other wider. These appear to have proceeded from the 
peripheral; but as the peripheral figured by Cope shows the costo- marginal sulci to have run 
low down on the peripherals, the presence of these loops on the costal is at present inexplicable. 
Similar irregularly meandering sulci are seen on other bones. The oblique hinder sutural edge 
of the costal probably articulated with the eleventh peripheral and with the suprapygal. The 
fourth costal scute may have occupied a portion of the suprapygal, as it does in Kinosternon. 
In the U.S. National Museum there is a neural, the second or fourth, which was collected by 
Mr. J. B. Hatcher, on Lance Creek, Wyoming. 
