400 FOSSIL TURTLES OF NORTH AMERICA. 
subacute free border of the lip the bone rises on the upper side to a point 105 mm. behind the 
front and then drops off suddenly. The greatest thickness attained is 70 mm. The upper 
surface of the lip is convex. There is no conspicuous notch where the gulo-humeral sulcus 
crosses the border. 
The entoplastron was about 245 mm. wide. Its length is conjectural. It was pointed in 
front. Its greatest thickness at the midline is 70 mm., while the thickness of the hyoplastron 
is 46 mm. 
The hinder lobe (fig. 617) had a length of about 160 mm. along the midline and a basal 
width of about 530 mm. Posteriorly there is a median notch 220 mm. wide and only 45 mm. 
deep. At the inguinal notch, on the upper surface of the lobe, a great wall begins and runs 
backward along the free border. The outer face of this wall is perpendicular and, at the 
notch, 100 mm. high. At the femoro-anal sulcus the height is 40 mm., and the outer face is 
inclined at an angle of about 45°. From the beginning the inner face slopes at an angle of 
about 45°. 
a : ees Bai: 
Of ‘, Vag ie a nar a 
\ / | 
Z ve ay 
4 i 2 “e 
} s } 
i \ 6 i 
ee 7 nt \ ie) j 
re 2 a, i i 
f Yi . ; 
p Lr - re 
Me : 
f 
an 
a8. (po 
. ton 
| | 
Fics. 618-620.—T estudo crasstscutata. Neurals and costals. 4. 
618. Third and fourth neurals. 619. Costal bone. 620. Costal bone. 
In the U.S. National Museum is a collection of fossil tortoise bones, No. 4963, which were 
collected near Tampa, Florida, by Mr. A. M. Lambert. They are believed to belong to this 
species. There are 2 successive neurals, the third and the fourth (fig. 618). They are remark- 
able for their size and great thickness. The third has a length of about 110 mm. and a width 
of 155mm. Itis crost by a deep sulcus. From each end of the bone the surface slopes toward 
this sulcus, so that the bottom of the latter is 15 mm. below the level of the ends of the bone. 
The fourth neural, like that of most other species of the genus, is much larger than the third 
and is octagonal in form. Its length is 130 mm.; its width, 200 mm.; and its thickness, 44 
mm. Each side was in contact with the third, fourth, and fifth costals. An estimate makes it 
probable that the carapace of this individual was about 4 feet in length. 
Fig. 619 represents the proximal end of a costal belonging to this collection, either the third 
or the fifth. Its greatest width is 150 mm., but at the distal end of the fragment the width is 
reduced to r11 mm. At the proximal end the thickness is 40 mm. Here it was in contact with 
