6 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. 62. 
The posterior lobe is 51 millimeters long and 57 millimeters wide 
at the base, whereas in the much larger type (male) specimen, the 
length of this lobe at the center is only 46.5 millimeters, and 53 
millimeters wide at the base, but which expands posteriorly to 68 
millimeters wide. It will thus be observed that the posterior lobe 
in the male is relatively much smaller than in the smaller female, 
compare Figures 5 and 6, a difference that prevails in the two sexes 
of the living K. flavescens. The posterior end is indented by a 
U-shaped notch, 7.5 inillimeters deep and 10 millimeters wide in the 
Fic, 5. PLASTRAL VIEW OF CARAPACE OF KINOSTER FIG. 6. PLASTRON OF KINOSTERNON ARIZONENSE. 
NON ARIZONENSE. No. 10163, U.S.N.M. TYPE. No. 10462, U.S.N.M. PARATYPE. FEMALE. AB, 
MALE. AB, ABDOMINAL SCUTE; AN, ANAL SCUTE; ABDOMINAL SCUTE; AN, ANAL SCUTE; EPI, EPIPLAS- 
FEM, FEMORAL SCUTE; HYO, HYOPLASTRAL BONE; TRAL BONE; HYO, HYOPLASTRAL BONE; HYPO, HYPO- 
HYPO, HYPOPLASTRAL BONE; XIPH, XIPHIPLASTRAL PLASTRAL BONE; XIPH, XIPHIPLASTRAL BONES. MORE 
BONE. ONE-HALF NATURAL SIZE. THAN ONE-HALF NATURAL SIZE. 
male but only slightly indented in the female. The posterior ex- 
tremities of the plastron end about 27 millimeters anterior to the 
posterior margin of the carapace. In the paratype this distance is 
only 18 millimeters. The bridge in the type has a width of 25 milli- 
meters, but in the smaller paratype it measures 29 millimeters fore 
and aft. The plastron at the center of the bridge in the type — 
measures 99 millimeters in width; the paratype 92 millimeters. 
The free borders of the plastra are acute on both front and hinder 
lobes, thickening slightly from the border inward, but nowhere 
does the plastron exceed 4 millimeters in thickness. The bevelled 
