EMYDID&. 395 
The posterior border of the bone is 5 mm. thick, while the anterior sutural border is 8 mm. 
thick. This is due evidently to the formation of a ridge on the fifth and sixth costals for the 
reception of the inguinal buttress. 
No. 1173 of the American Museum forms Cope’s third specimen. There is present a 
portion of the first costal with the articular surface for the axillary buttress. There is a rough 
drawing by Cope on which this bone is traced as belonging to the xiphiplastrals. This bone 
belonged to a much larger individual than that represented by No. 1181, but the scar for the 
buttress is no longer. This costal was at least 35 mm. wide and is 7 mm. thick where it joined 
the first and second peripherals. The outer surface is smooth. With this lot is a portion of the 
third right peripheral, excavated at the hinder end to form a part of the sternal chamber. Fig. 
387 represents the sutural surface which articulated with the second peripheral. It will be 
seen that the free border is broadly rounded. Fig. 388 presents the outlines and a view of 
the anterior articular surface of a hinder free peripheral. This is recurved and has an acute 
edge. The surface is uneven; and the sulci are narrow but sharply imprest. 
No. 1258 appears to represent another portion of Cope’s principal specimen. Among the 
bones is an entoplastron, but not the one described by Cope. The one which furnisht Professor 
Cope’s figure 12 is not one-half the size of nature, as stated, but four-sevenths. The breadth of 
the entoplastron of No. 1258 is 37 mm., its antero-posterior extent 24 mm., 2 mm. less than 
that given by Cope. The longitudinal sulcus is very obscure, while te humero- pectoral 
plainly crosses the bone about the middle of the length. The internal face of the bone is badly 
weathered, so that little regarding the position of the bone can be determined therefrom. 
The anterior border is damaged for most of its extent. There is a piece of the left hyoplastron 
present, but it is impossible to say whether the two bones belong together. What appears to be 
the free border of the right hyoplastron is present. The edges are acute. The beveled surface 
on the upper side attains a width of 15 mm. and a 
thickness of g mm. Two portions of the epiplastra 
f are present, but their proper positions are difficult to 
determine. They are acute- edged and they thicken 
rapidly, the beveled surface attaining a thickness of 
II mm. and a width of 14 mm. At the inner border 
ee the thickness is diminisht suddenly. 
387. 388. a The fragment of the hinder lobe figured by Cope 
- (his fig. 13) appears to indicate the presence of a 
EiGS Jo7 SND 388.-—Echmatemys testu-  well-developt inguinal buttress, whose base extended 
ae ee X1. No. 1173 inward about 20 mm. from the free border. At the 
ieide wi. suture between hypoplastron and xiphiplastron the 
387. Section at anterior end of thirdright peripheral. beveled upper border has a width of 15 mm. and here 
chs sa set ola Secreta slow Hacites' »she bane 1s 8.5 mm. thick. The inner border of the 
beveled surface is bounded by a considerable groove. 
The free border is acute. The lower surface of this hinder lobe was flat transversely and 
turned up posteriorly. The abdomino-femoral sulcus crost the plastron somewhat in front of 
the inguinal notch. 
Cope believed there was an undivided intergular, but the writer finds nothing to sustain 
this opinion, and it is improbable. Undoubtedly the species is an emyd, and the presence of 
an intergular, single or divided, would probably be unique. The proximal end of a costal, the 
second or the fourth of the left side, has a width of 20 mm. and a thickness of 8.5 mm. The 
longitudinal sulcus traverst the bone at a distance of 7 mm. from the neural border, showing 
again that the vertebral scutes were very narrow. While the surface is uneven, there is no 
swelling outside of the sulcus, differing thus from the others described. 
Echmatemys euthneta (Cope). 
Plate 46, fig. 1; text-figs. 389-391. 
Emys euthnetus, Core, Sixth Ann. Report U. S. Geol. Surv. Terrs., 1872 (1873), p- 628. 
Emys euthneta, Cope, Vert. Tert. Form. West, 1884, pp. 129, 133, plate xviii, figs. 34-42.—Hay, 
Bibliog. and Cat. Foss. Vert. , 1902, p. 447. 
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