344 FOSSIL TURTLES OF NORTH AMERICA. 
The figure itself is incorrect. His fig. 21 is that of a bone 7 mm. long and 8 mm. wide. The 
bones figured indicate a turtle which had a carapace about 100 mm. long. The originals of 
Cope’s hgs. 20, 21, and 22 are in the U.S. National Museum. We are not informed by that 
writer whether or not these bones belonged to a single individual. If they do, his fig. 21 repre- 
sents the seventh neural and his figure 20 the eighth. Cope’s fig. 22 represents a peripheral. 
In its upper border there is a pit for the end of a rib. The fore-and-aft extent of the bone is 
gmm. Its free border is broken away, but the height of the bone was somewhat more than 
1omm. It is considerably recurved. Its ebro is between 3 mm. and 4 mm. The sulci 
crossing it are broad and rather deeply imprest. 
Palzotheca terrestris Cope. 
Paleotheca terrestris, Cope, Palewont. Bull. No. 1, 1872, p. 464; Proc. Amer. Philos. Soc., x11, 1873, p. 464. 
Emys terrestris, Cope, Sixth Ann. Report U. S. Geol. Surv. Terrs., 1872 (1873), pp- 625,629; Vert. Tert. 
Form. West, 1884, pp. 129, 130, 131, plate xviii, figs. 23-25.—Hay, Bibliog. and Cat. Foss. Vert. 
N. A., 1902, p. 448. 
Of Cope’s specimens of this species, three in number, those parts represented by his 
figs. 23, 24, and 25 of the plate cited are in the U.S. National Museum and have the number 
2107. All his materials were found in Bridger strata, but the exact locality and level are 
nowhere mentioned. ‘They were undoubtedly secured somewhere in the region about Fort 
Bridger, Wyoming. 
Of his type specimen Cope figured 1 neural, 1 costal, and the right epiplastron. In his 
description he probably intended to give the measurements of the aan figured. At any rate, 
there is some error, for it is not probable that any neural was twice as wide as long. The neural 
feured is g mm. long and 13 mm. wide. The width of the costal is given as 11 mm., whereas 
the width of his figure 25 1s only a little more than 10 mm. 
This species is stated by Cope to differ from P. polycypha in having bones at once larger 
and thinner; and this is confirmed by a comparison of the neurals of fhe two species, as they 
are figured. As in the case of P. polyc ypha, there was a dorsal carina, and this was interrupted 
by the deeply imprest scutal sulci which crost it. 
The epiplastron is 19.5 mm. long and 18 mm. wide. The lip projected abruptly from the 
general outline about 3 mm. and was truncated. The anterior edge was acute. At its base the 
lip was 21 mm. wide and nearly as wide in front, the width of the half of it present being 10 mm. 
On the upper side of the lip the bone was thickened backward for a distance of about 11 mm., 
the greatest thickness being 4.5 mm. 
Cope’s fig. 254 gives a view of the hinder articular border of a costal. This is 3 mm. thick 
at the proximal end of the bone, but at the lower end is 5 mm. This costal appears to be the 
fifth of the right side; and with the succeeding one formed a ridge for the inguinal buttress. As 
shown by Cope’s fig. 25a, at the lower end of the bone and at its hinder border there was the 
half of an excavation for this buttress. About the distal half of the costal is broken away and 
the buttress therefore ascended one-half the height of the costal. The rib-head is hardly dis- 
cernible. The proximal end of the costal does not join accurately the neural of Cope’ s fig. 233 
hence it is concluded that this neural is the third. “The costo-vertebral sulcus (Cope’ s fig. 25) 
crosses the costal at a distance of 5 mm. from the proximal end, from which fact it 1s concluded 
that the fourth vertebral scute was about 28 mm. wide. The turtle was undoubtedly a small 
one with a thick, heavy shell. 
Cope states that the articulations of the bridge with the costals were not known to him. 
No specimens belonging to this species or to P. polycypha were secured by the expedition 
from the American Museum of Natural History into the Bridger beds 1n 1903. 
Genus HYBEMYS Leidy. 
Insufhiciently known emydoid turtles, the upper surface of whose peripherals was orna- 
mented by a row of hemispherical bosses, each of which was crost by the suture between the 
two peripherals on which it rested. 
Type: Hybemys arenaria Leidy. 
