EOCENE TESTUDINATA. 
53 
of the specimens, portions of plastron with the free borders marked by a 
broad, smooth band, which thickens inward to an abrupt, descending 
margin. The surface of this border is regularly marked with parallel, 
obtuse ribs. The vertebral bones on which the median rib is obsolete have 
their lower surface produced in a projecting point on each side of the rather 
narrow excavation for the extremity of the vertebra which precedes each. 
The size is about that of the Dermatemijs vyomingensis, Mid the robustness 
of the bones similar. 
The reference of this species to the genus Bermatemys is provisional 
only, and is based on specific resemblances to the B. vyomingensis^ Leidy. 
EMYS, Brongniart. 
Tortoises having the carapace and plastron of this genus were abundant 
in New Mexico during the Wahsatch epoch. Fragments of these portions 
of the skeleton are very commonly found, and not unfrequently the geolo¬ 
gist meets with them in a nearly entire condition. Materials for the deter¬ 
mination of two species were obtained by myself in 1874. 
Emys lativertebralis, Cope. 
• Plate xxvii, figs. 1-3; Plate xxviii, figs. 1-2. 
Emys latilahiatus. —System. Cat. Vert. Eocene, New Mexico, U. S. Geog. Survs. W. of 
lOOtli M., 1875, p. 36, not of Paleontological Bulletin, No. 3, p. 3, and U. S. 
Geol. Survey of the Terrs., 1872, p. 626. 
I found the larger portion of the carapace and plastron of a specimen 
of this species piled together and free from the matrix, and considerable, 
though less numerous, portions of four other individuals of the same, in a 
similar condition. 
The characters which distinguish this species from the vyomingensis, 
to which it is allied, are the following: The vertebral bones are, excepting 
the first, wider than, or as wide as, long; the mesosternal bone is truncate 
behind, and is not crossed by the common suture of the pectoral and humeral 
dermal scuta; the postabdominal bones are divided by a deep semicircular 
excavation behind, which separates widely their posterior apices. In the 
E. vyomingensis^ the vertebral bones, except a few of the posterior, are longer 
than wide; the mesosternal bone is angulate behind, so as to be ci’ossed by 
