60 FLORIDA GEOLOGICAL SURVEY-EIGHTH ANNUAL REPORT. 
the rear of the first marginal scute, the second and third marginals, 
and most of the fourth. At the sulcus between the second and 
third marginals the thickness is 13 mm. In this specimen the bor¬ 
der at the third marginal is not much curved upward but in three 
other specimens it is considerably curved. The upper surface is 
rough. 
Figure 3 of plate 5 presents a view of a fragment on which 
are wholes or parts of the third, fourth, fifth and sixth marginal 
scutes. This fragment shows that there is a rather prominent keel 
which lies above the bridge and runs through the marginals shown. 
Figure 4 of the same plate presents a view of a strip of the second 
costal scute, a considerable part of the third marginal and parts 
of the seventh and eighth marginals. The upper surface of this 
fragment, No. 5478, is relatively smooth. This piece and another, 
No. 5469, present the lateral hinge line. The surface of the hinge 
is flat and 8 mm. wide. The border of the carapace which bears 
this hinge is turned inward at nearly a right angle with that part 
of the peripherals which is above the lateral keel. This keel is 
nearly on a level with the upper edge of the lateral hinge and dis¬ 
tant from it about 15 mm. 
A fragment of the carapace, No. 1782, has only feeble indica¬ 
tions of sutures. A part of the area occupied by the fifth vertebral 
scute shows that the latter had a width of 45 mm. At the free 
edge of the bone the eleventh marginal was 20 mm. long, the 
twelfth, 17.5 mm. The greatest height of the former was 26 mm.; 
that of the twelfth, at the midline, 15 mm. The hinder part of 
the tenth scute had a height of 27 mm. The border of the cara¬ 
pace, as here represented, is moderately flared outward, more than 
in T. ornata, about as much as in T. major. 
Another fragment, No. 54S0, (pi. 5, fig. 5), presents both 
eleventh peripheral bones, the pygal and the suprapygal. The su¬ 
tures are open. The suprapygal is nearly triangular, 38 mm. wide 
and 27 mm. high. The pygal is 20 mm. wide, 21 mm. high, and 
10 mm. thick. The peripherals are 26 mm. wide on the free bor¬ 
der and 28 mm. high. They are moderately flared outward. The 
eleventh marginals were at least as high as the eleventh peripheral 
and the twelfth marginals are just as high as the pygals. The fifth 
vertebral scute was at least 40 mm. wide. 
Unfortunately, besides the piece just mentioned, we have 
