318 FOSSIL TURTLES OF NORTH AMERICA. 
the front pair of peripherals, and the hinder peripherals are acute. The borders of the carapace 
are nowhere notcht. The surface is smooth or relieved only by longitudinal striations. 
The nuchal bone 1s 53 mm. long, 34 mm. wide in front, 
and 60 mm. where widest, the table presenting the dimen- 
Plements a EES We Met sions of the remaining median bones. 
The table below presents the dimensions of some of 
Neural 1 36 21 the peripherals and of the vertebral and marginal scutes. 
Siar 2 7 ae The third peripheral has a height equal to 56 per cent. 
Neural ao: 35 24.5 of the height of the first costal, from the neural to the 
Neural 5 29 27 peripheral. 
ee e: ze ee The vertebral scutes are relatively narrow and the 
Neural 8..... 16 18.5 sides of the second and third are moderately bracket- 
Suprapygal 1.. 33 25 shaped. The interior and posterior are expanded. 
SETAE TERY Pen: 38 83 The nuchal scute is 10 mm. wide posteriorl nd its 
Pygal am 38 Pp iorly ar 
length is 1g mm. The costo-marginal sulci run well below 
the costo-peripheral suture. The dimensions of five of 
the marginal scutes are given in the table below, on the might. 
The total length of the plastron (plate 48, hg. 2; text-fig. 412) is 317 mm. The anterior 
lobe is 88 mm. long and 126 mm. wide at the base, the length being thus 70 per cent. of the 
width. ‘The lateral borders run directly forward to the hyoepiplastral suture, then curve to 
the lip. This had a width of 56 mm. and had a tooth on each side. The lip does not extend 
Dimensions of peripherals. Dimensions of vertebral scutes. Dimensions of marginals. 
Width = Width : : Length 
: NV sreates = i 3 
No. Height. of free of upper No. Length. . ah SES No. BGI aeetest of free 
: : in front. width. in front. height. 
border. border. border. 
I 39 38 17 I 58 74 74 I 19 2 32 
2 40 38 23 2 67 37 57 2 24 27 35 
3 41 48 26 3 68 35 53 3 20 21 40 
6 48 48 46 4 78 37 58 4 21 27 44 
8 53 42 31 5 50 24 67 9 38 43 42 
as far forward as the nuchal bone. The thickening on the upper side of the symphysis of the 
epiplastrals extended backward 25 mm. The greatest thickness of the epiplastrals is 13 mm., 
and between these thickenings the bones are slightly channeled longitudinally. The thickness 
of the symphysis is 13 mm. The horn-covered surface of the upper side of the epiplastron, at 
the suture with the hyoplastron, is 18 mm. wide. The entoplastron 1s 47 mm. long and 57 mm. 
wide. It is pointed in front; rounded behind. 
The bridge has a width of 136 mm. 
The hinder lobe is 105 mm. long, and 140 mm. wide at the base. The length is therefore 
75 per cent. of the width. The buttresses arise far within the free border of this lobe. The 
beveled surface of the upper lobe (fg. 413), at the suture with the xiphiplastrals, 1s 28 mm. 
wide. The free borders of the lobe are acute. The posterior notch is about 28 mm. wide and 
6mm. deep. The posterior buttresses appear to have extended at their bases about half-way 
to the midline. How high they rise has not been determined. 
The gulars are 45 mm. long; the humerals, 20 mm.; the pectorals, 63 mm.; the abdomi- 
nals, gl mm.; the femorals, 52 mm.; and the anals, 45 mm. 
The axillary scute is large, extending outward and backward to form contact with the 
fhitth marginal for a distance of 6 mm. The inguinal scute extends forward within 13 mm. of 
the sixth marginal. 
From EF. naomi the species differs in having a smoother shell, with less deeply imprest 
channels for the sulci, and in having narrower neurals. The carapace of FE. stevensoniana is 
more contracted in front. &. shaughne sstana is set off by the bluntly rounded anterior border 
of the carapace. From F£. «gle the present species is distinguisht by the larger axillary scute, 
the deep grooving of the carapace, the lower position of the costo- marginal sulci, the relatively 
broader and eioriey anterior lobe of the plastron, ete. In £. ocyrrhoé aie carapace 1s smooth, 
