TESTUDINIDA. 433 
The roof of the mouth (fig. 567) resembles closely that of 7. osborniana. The outer ridge 
of the masticatory surface is strongly developt and dentated. Anteriorly it continues forward 
on the premanilla of its side; so that between the right and left ridges there is, in the pre- 
maxillary region, a deep furrow. The inner ridge oF the masticatory surface is broad and 
rough behind and divided by a deep longitudinal groove. The palate is deeply excavated. On 
each pterygoid there is a hookt ectopterygoid process. The distance across the two pterygoids 
is 30 mm. 
The lower jaw (figs. 568, 569) is large and heavy. Its length from the symphysis to the 
angle is 98 mm.; its height at the connor process, 32 mm.; at the symphysis, 21 mm. Each 
ramus has its masticatory surface divided longitudinally by a deep groove. From the outer 
cutting-edge sharp ridges run down on the outer face of the dentary. 
The total length of the shell is 922 mm.; the width, 725 mm. The height can not be 
exactly Be enned: on account of injuries to the carapace (plate 76). The middle region of 
this has been Broken in, and the fragments considerably disturbed, while the unbroken portions 
of the costals and to some extent, the peripherals, have been somewhat deprest. It appears, 
Fics. 568 aND 569.—Testudo impensa. Skull and lower jaw of type. 3. 
568. Skull, right side. 569. Lower jaw, seen from above. 
however, improbable that the shell ever had as great height as that of 7. osborniana. The 
width of the carapace is 78 per cent. of the length; whereas, in T. osborniana the width is 71 
per cent. The peripherals have practically the same form as in the last-mentioned species, 
but those of the bridge regions do not appear to have had relatively as great height. Neither 
do the peripherals of the posterior region descend so steeply as in 7. osborniana. In the latter 
the Py gal and the adjoining peripherals slope forward from the perpendicular only about 15° 
or 20°; whereas, in 7. impensa the forward slope is about 45°. A part of this angle is due 
possibly to depression, but this seems improbable. The anterior outline of the carapace 1s 
convex, not straight or concave as in T. osborniana; and the anterior border does not pass so 
abruptly into the lateral border. 
On account of the crushing in of the upper part of the carapace, it has been difhcult to 
determine the dimensions of the neurals, but the following statements may be relied on. The 
first neural (fig. 570) is oval in form, and the width has been close to 70 mm. The second is 
octagonal, and had a width, where greatest, of 120 mm. The third is hexagonal, 73 mm. 
long and 97 mm. wide. The fourth is octagonal, 76 mm. long, 112 mm. wide. The sixth 1s 
hexagonal, 70 mm. long and 100 mm. wide. The seventh is 63 mm. long and 118 mm. wide. 
ashe third and the an costals are expanded at their proximal ends and each is 1n con- 
tact with three neurals. 
The pygal is 145 mm. wide at its upper end, 114 mm. at the free border. The first supra- 
pygal has the usual bifurcate form and is in extensive contact with the pygal and the eleventh 
peripherals. The second suprapygal is 90 mm. long and 84 mm. wide. 
The plastron (plate 77; text-fig. 571) has a total ‘length of 805 mm. The width, from the 
outer border of the hy oplastron oi one side to that of the other, is650 mm. There is a con- 
siderable concavity in the region between the inguinal notches. The width of the anterio1 
28 
