DERMATEMYDID#. 279 
Genus ANOSTEIRA Leidy. 
Plastron articulating with the carapace by sutures. Plastral bones 9, the entoplastron 
lanciform. Hinder plastral lobe small. Nuchal bone without costiform processes. Ten pairs 
of peripherals; 8 pairs of costals; 7 neurals. The eighth pair of costals meeting on the mid- 
line. Epidermal scutes developt at least on the carapace. The vertebrals greatly modified. 
Type: Anosteira ornata Leidy. 
Dr. Leidy did not definitely refer this genus to any family, but regarded it, with Baéna, 
Chisternon, and Baptemys, as apparently intermediate to the Pleurodira and the Chelydride 
(Contrib. Ext. Fauna, etc., p. 341). Cope (Amer. Naturalist, xv1, 1882, p. 990; Vert. Tert. 
Form. West, 1884, p. 112) arranged the genus under the Chelydride; but in the same family 
in close relation with Anosteira he included also Claudius. He arranged Dermatemys among 
the Emydide. Baur (Ann. Mag. Nat. Hist., ser. 111, 1889, pp. 58, 27 6; Proc. Acad. Nat. Sci. 
Phila. 1891, p- 420) favored placing it with either Staurotypus or peter ae according as 
the entoplastron might or might not be found to be present. Mr. Lydekker (Cat. Foss. Rept., 
ut, 1889, p- 143) places the genus in the subfamily Anosteirinz under the Chelydrida. Hay 
in 1902 (Bibliog. and Cat. Foss. Vert. N. A., p. 446) raised this group to family rank, but this 
had already ee suggested by Baur. 
The nearly complete shell described below, presenting as it does the entoplastron, enables 
us to refer the genus definitely to the Dermatemydidae. The plastron resembles closely that 
of Stauroty pus Seah. The presence of the costiform processes in the living members of the 
family are not regarded as being of essential importance. 
There can be hardly any “doubt that Pseudotrionyx Dollo, of the Middle Eocene of Bel- 
gium, is a genus closely related to Anosteira. 
Anosteira ornata Leidy. 
Plate 43, figs. 1, 2; text-figs. 352-354 
Anosteira ornata, Leipy, Proc. Acad. Nat. Sci. Phila. 1871, p. 102; Ann. Report U. S. Geol. Surv. 
Montana, etc., 1871 ‘(187 2), p- 370; Contrib. Ext. Fauna West. Terrs., 1873, pp. 174, 341, plate xvi, 
figs. 1— ~6.-Hay, Bibliog. and Cat. Foss. Vert. N. A. 1902, p. 4473 Bull. Amer. Mus. Nat. Hist., 
XXII, 1906, p. 157, hes: 25.3: 
Anostira ornata, Cope, Ann. Report U. S. Geol. Sury. Wyoming, etc., 1872 (1873), p. 621; Amer. Nat- 
uralist, Xvi, 1882, p. 989, fig. 7; Vert. Tert. Form. West, 1884, p. 128.—Do to, Bull. Mus. Roy. 
Belgique, 1v, 1886, p. 93, pl. 1, figs. 7, 8. 
This beautiful and interesting species was based originally on 4 individuals, some of 
which had been discovered at @hnreh Buttes and others at Grizzly Buttes, Wyoming. Where 
these types now are the writer does not know. It is possible that some of them are included 
under No. 4062, of the U.S. National Museum. The specimen figured by Leidy was obtained 
somewhere in the neighborhood of Fort Bridger. It is now in the collection of the Phila- 
delphia Academy. All of his specimens appear to have come from the lower portion of level 
B of the Bridger Eocene. The American Museum expedition of 1903 found fragmentary 
specimens of the species at Grizzly Buttes and on Cottonwood Creek. The expedition of 
1g05 secured at Henry’s Fork a nearly complete shell, which is here described and figured 
(plate 43; text-figs. 352, 353): This comes from a higher level than the other known specimens. 
Leidy’s reconstruction of this species aciabtted to it II pairs of peripherals. Dr. Baur 
was the first to correct this error. The complete specimen just mentioned confirms Baur’s 
statement. 
The specimen found at Henry’s Fork belongs to the third division of level C. It has the 
number 6132, of the American Museum. The specimen is slightly crusht. The neurals 
(fig. 352) are all missing, as well as the left front part of the carapace. In form the carapace 
is not so much excav ated i in front as is represented in Leidy’s figure. Other specimens of the 
species show as little excavation. 
The total length of the carapace (plate 43, fig. 1; text-fig. 352) along the median line is 
125mm. The widthis 105 mm. The nuchal is slightly damaged, but its length has been close 
to 20 mm. and the width the same. The free border is subacute; the thickness at the midline 
