TESTUDINID&. 307 
expected. No part of the nuchal appears. The first neural was wider than the second, and in 
contact with the second costal. Its greatest width was near 64 mm., while the second has 
measured 55 mm. in width. As in some specimens of S. nebrascensis and in probably all 
individuals of the John Day species of the genus, the third neural was tetragonal. Correspond- 
ing to this condition, the third costal was in contact with the second, third, “and fourth neurals. 
The costals are only slightly modified as respects the widths 
Proximal Distal of the opposite ends of ‘each. The measurements shown in the 
sie end. end. table taken from Sinclair’s description and illustration show the 
extent of the modification. 
= a eg The carapacial scutes resembled closely those of S. nebra- 
; Be 67 scensis. An estimate makes the first vertebral scute to have 
5 2 ie been about 184 mm. wide in front. The second vertebral was 
a) jot siz 
about 108 mm. wide. 
The plastron (text-fig. 503) was, according to Sinclair, broken 
away at the extremity of the epiplastral lip. It must therefore have been rounded. The 
anterior lobe had a length of about 100 mm., the base a width of 200 mm., resembling thus 
the anterior lobe of 8. pele ascensis. The entoplastron is rhomboidal in form, thus resem- 
bling that of some species of Testudo. Its length is 81 mm., its width is 88 mm. The 
portion of the plastron present evidently eeeccd backward to near the hinder border of 
the hypoplastron; but did not reach the inguinal notches. The bridge must therefore have 
had a width of at least 172 mm. 
The sulci separating the scutes of the plastron are stated to be very obscure. The gulars 
and humerals resemble those of S. nebrascensts. 
It appears to be quite certain that this species belongs to the genus Stylemys. It appears 
to differ from all the others in having a very broad first neural, which comes into contact with 
the second costal bone, and in having the entoplastron more pointed behind. From the known 
John Day species it differs in having the costal bones less wedge-shaped. 
Genus TESTUDO Linneus. 
Carapace extensively joined to plastron by suture. Inguinal buttresses rising little, if any, 
above the costo- peripheral sutures. Second and fourth neurals usually octagonal; the third 
and fifth usually quadrangular. Epiplastral lip usually projecting abruptly from the general 
contour of the anterior lobe. Plastron notcht behind. Crushing- surfaces of jaws with longi- 
tudinal ridges and grooves. No median longitudinal ridge in front of the choanz. Digits 
much shortened and foot club-shaped. 
Type: Testudo greca Linnzus. 
From both Hadrianus and Stylemys this genus is distinguisht by the much higher grade of 
differentiation which has been attained by the elements of the shell. From Style mys it 1s 
further distinguisht, as it is also from Gopherus, in having no longitudinal ridge in the midline 
of the upper jaw in front of the choana. Some living species ‘have the neurals and costals 
little more differentiated than in Stylemys, and in T. inusitata, described below, none of the 
neurals is octagonal or quadrangular. 
ANALYSIS OF THE KNowN NortTH AMERICAN Fossit Species oF Trstupo. 
A‘. Oligocene species: 
Titanotherium beds. 
Peripheral sulci deeply imprest; epiplastral lip more than twice as wide as long .. brontops 
2. Costals very thick; deeply imprest by lines of growth of the horny scutes exornata 
aa. Oreodon beds. 
3. Lip nearly as wide as long; its sides parallel . thomsont 
4. Shell flattened; no octagonal neural; epiplastral lip abruptly projecting, tootht 
in front . latrcunea 
5. Lip truncated, three times as wide as long... ; Irgonta 
6. Lip truncated, short; pectoral scutes about one-fourth as wide as abdominals am phithorax 
7. Lip square; the gulars not reaching the entoplastron quadrata 
8. Lip narrow and wedge-shaped cultrata 
