ART. 5. A NEW FOSSIL TURTLE—GILMORE, oO 
Measurements of vertebrals in millimeters. 
Length. Width. 
No. 
Type. Paratype. Type. Paratype. 
Ma ere eer acre hia slelayaie & Sree sini aes aetee mel eee 35 46 37 
DIE BR LVS ON SEL POISE OSEL SES UE 35 35 43 37 
Se eee Be gt. HE hs a Sica Nee of en reds 32. 5 35 50 44 
AMON AS TEP Paes alain ts Maier antic 2, craps teicicle, seahelars 37 31.5 46 38 
SER. SEER TAUPE TENET Sh bS. SEO Te 39 26 50 36 
There are eleven pairs of marginal scutes as in the living species. 
The costo-marginal sulci, on the peripherals of the anterior half of the 
carapace, cross them well below the middle of their height, rising 
slightly on the median ones, but when the eighth is reached an 
Fic. 4. CARAPACE OF KINOSTERNON ARIZONENSE. NO. 10462, 
U.S.N.M. PARATYPE. FEMALE. VIEWED FROM THE LEFT 
SIDE. ONE-HALF NATURAL SIZE. 
abrupt increase in size of the marginals takes place as shown in 
Figures 3 and 4, as in the living K. flavescens. The intermarginal 
sulci descend a little in front of the middle of the length of the 
peripherals. 
In the type the front lobe of the plastron is missing, but in the 
paratype the plastron is almost perfectly preserved. The description 
to follow is based largely on that of the paratype. It is composed of 
eight bones the entoplastron being absent. The front lobes are hinged 
in both specimens, see Figures 5 and 6, the hinder ones being rigidly 
fixed. This species differs from K. flavescens in having a broadly 
V-shaped hinge line whereas in the living species it runs nearly 
straight across the plastron. 
The greatest length of the plastron at the center is 117 millimeters, 
with a greatest transverse diameter of 92.5 millimeters. The an- 
terior lobe is 41 millimeters long and 65 millimeters wide at the base. 
The width of this lobe grows gradually less for more than half its 
length, then rounds in rapidly toward the center which is slightly 
truncated. In K. flavescens this lobe narrows in more rapidly from 
the hinge forward, thus giving it a more pointed appearance. 
