332 FOSSIL TURTLES OF NORTH AMERICA. 
As shown by the fifth, seventh, and eighth peripherals the costo-marginal sulci ran near the 
costo-peripheral sutures, being distant 8 mm. or less. 
As stated previously, the plastron (fig. 436) has a total length of 300 mm. The anterior 
lobe measures 87 mm. in length and has a width of 124 mm., the length thus being 70 per cent. 
of the width. It contracts a little in front of the axillary notch, then runs directly forward some 
distance in front of the hyoepiplastral sutures, then curves rapidly to the lip. The latter is 
49 mm. wide. On each side it presents a stout tooth. Behind these teeth the thickness of the 
bones is 11mm. The thickened portion of the epiplastral (fig. 437) continues backward 26 mm. 
Outside of the gular sutures, on the upper side, the horn-covered surface is 18 mm. wide, 
increases to 20 mm., and is reduced at the hyoepiplastral suture to 16 mm. The entoplastron is 
35 mm. long and 60 mm. wide. The anterior buttresses arise some 15 mm. or more within the 
border of the anterior lobe and rise to a height of at least 63 mm. They are about 30 mm. 
wide and 7 mm. thick. The width of the bridge is 132 mm. 
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Fics. 436-438.—Echmatemys egle. Plastron of type. 
436. Plastron. X}. 437- Upper surface of anterior lobe. 4. 
438. Upper surface of hinder lobe of plastron. 4. 
The hinder lobe is go mm. long and 126 mm. wide at the base, the length being thus 71 per 
cent. of the width. Itis rather conspicuously notcht at the outer ends of the femoro-anal sulci. 
The notch in the rear is rather deep, 13 mm., and its width is 36 mm. The beveled area on the 
upper side of the hinder lobe (fig. 438) commences near the outer border of the buttress, 
increases in width to the hypoxiphiplastral suture, where it is 23 mm. wide, and then diminishes 
to1omm. The bases of the posterior buttress extend more than half-way from the border of 
the hinder lobe to the midline. Their summits are fully 65 mm. above the upper surface of the 
hinder lobe. They are 25 mm. or more wide and 7 mm. thick at half their height. 
The gulars have a length, on the midline, of 47 mm.; the humerals, 22 mm.; the pectorals, 
58 mm.; the abdominals, 72 mm.; the femorals, 47 mm.; the anals, 34 mm. 
The portions of the third and fourth peripherals present show that the axillary scutes fail 
to reach the fifth marginal scute by 20 mm. The inguinal scutes are not well displayed. 
A second specimen referred to this species is No. 5976 of the American Museum. It was 
obtained in 1903, in the western portion of Grizzly Buttes and in level B. It is represented by 
