300 FOSSIL TURTLES OF NORTH AMERICA. 
This is one of the two species of emyd turtles described by Professor Cope trom the Green 
River beds in the region of Black Buttes, the other species being E. megaulax. Emys euthneta 
is said to have been represented by numerous specimens and to have been abundant in the 
red beds which lie between those identified as belonging to the Green River and the Bridger 
epochs at Black Buttes. The figured bones of the species are in the National Niscame at 
Washington. They have the catalog number 4125. 
In ‘he American Museum there are three lots, parts of the Cope collection, which appear 
to belong to this species. The parts which were figured by Cope were 3 neurals, 4 peripherals, 
1 epiplastron, and a part of 1 xiphiplastron. All these, it is stated, were found together and 
were supposed to belong to a single individual. The neurals displayed no dorsal keel, the 
scutal sulci were not deeply imprest, and the surfaces of the carapacial bones were smooth. 
The length of the carapace of this individual must have been about 190 mm., the three neurals 
taken together measuring 49 mm. One neural, probably the third (Cope’s fig. 34), had a 
length of 19 mm. and a width of 15.5 mm., and a thickness of 4 mm. The A ele were not so 
wide in proportion to their length as in E. megaulax. The peripherals resemble those of F. 
megaulax, but they were not so deeply imprest by the sulci. The peripheral represented by 
Cope’ s fig. 37 is apparently an anterior second. Itis 8 mm. thick where it joined the third. 
Cope’s fis. 38 appears to represent the ninth peripheral of the right side, while his fig. 40 shows 
probably mhe eighth of the left side. The border which articulated with the seventh is 7mm. 
thick; that w hich articulated with the ninth is 6 mm. thick. Cope’s figure of the epiplastron 
shows correctly that the lip projected abruptly for a short distance, and was little, if at all, 
notcht at the midline. It is rounded off both above and below and has the free border obtuse. 
Its greatest thickness is 6 mm. It is doubtful how near the midline the fragment approacht, 
so that the width of the lip is uncertain. The hinder lobe is broadly notcht and the beveled 
surface on the upper side is relatively narrow. The thickness of the border i is 5 mm. anteriorly. 
Here the free edge is obtuse but posteriorly it becomes acute. 
In the Cope collection of fossil reptiles, in the American Museum of Natural History, 
there are four lots of bones which are labeled by Cope as having come from the “‘red beds” 
of Black Buttes and were regarded by him as belonging to his Emys ys euthneta. These bear the 
catalog numbers 111g, 1174, 1176, and 1182. Nos. 1176 and 1182 together present nearly 
the whole of the plastron, except the epiplastron and the entoplastron. No. 1182 furnishes 
most of the hyoplastron of the right side and most of the hy poplastron of the left side. These 
bones are relatively thin. 
The plastron had a total length of nearly 240 mm. At the crossing of the median longi- 
tudinal suture and the hyohy poplastral suture the thickness is 7 mm. On account of some 
missing fragments, the length of the hyoplastron can not be exactly determined. The anterior 
lobe has a svidth of Ee 120 mm. The free border of the epiplastral process is acute, but 
soon the bone thickens to8 mm. At the hy oepiplastral suture the beveled surface on the upper 
side is 10mm. wide. No groove separates it from the surface beyond. The humero- pectoral 
sulcus, deeply sunken, crosses the free border of the bone 14 mm. behind the suture just 
mentioned. It appears almost certain that this sulcus did not touch the entoplastron. A 
deeply imprest sulcus cut off an axillary scute, only a part of which was situated on the hyo- 
plastron. The pectoro-abdominal sulcus crosses the bone at a distance of 1g mm. in front of 
the hyohypoplastral suture, measured at the midline; measured at the free border of the bone 
the distance is 30 mm. This sulcus is narrow and shallow. On the upper side of the bone, 
on the outer two-fifths, a strong axillary buttress arises for articulation with the first costal. 
The hypoplastron has a length of 70 mm. The width of the hinder lobe was close to 105 
mm. The free border has an acute edge. The superior beveled surface has a width of 10 mm. 
at the hypoxiphiplastral suture. No groove intervenes between this surface and that beyond. 
At a distance of 20 mm. from the free border the thickness of the bone is 8 mm. The inguinal 
buttress rises from the upper surface of this bone at a line less than half the divtance, from 
the free border to the midline. The abdominal scutes of this individual had a length of about 
58 mm. A fragment of the first costal (fig. 389) shows that the axillary buttress of this turtle 
ascended a distance of 20 mm. on the inner surface of the costal. 
Specimen No. 1176 (plate 40, fg. 1) presents the nearly complete hypoplastron and the 
complete xiphiplastron. The individual was only shghtly smaller than the preceding, the 
