422 FOSSIL TURTLES OF NORTH AMERICA. 
55 mm. thick. The posterior lobe is 173 mm. long to the apices of the xiphiplastra, and 1s 370 
mm. wide at the base. The posterior notch is 110 mm. wide and 45 mm. deep. At the inguinal 
notch the edge of this lobe forms a wall about 55 mm. high, having a rounded outer face and a 
sloping inner face. Posteriorly the wall diminishes rapidly in height, so that the thickness at 
the xiphiplastral apices is only 30 mm. 
The entoplastron is rhombic in form, 156 mm. long in the midline, 195 mm. wide. The 
hyoplastra meet along the midline for a distance of 176 mm., the hypoplastrals 156 mm., and 
the xiphiplastrals 145 mm. ; 
The nuchal scute is about 30 mm. long and wide. The marginal scutes rise to the sutures 
between the peripherals and the costals. The supracaudal scute seems not to have been 
divided in the midline. It has a width along the free border of 
vie pais 200 mm. The vertebral scutes are very wide, especially those 
ceute, | Eeseth. | ea behind the first. The table gives the dimensions. 
The gular scutes extend backward on the entoplastron. 
The humerals have an extent of 100 mm. along the midline. 
I 160 160 : ata 
: aa aie The pectorals are 73 mm. antero-posteriorly at the midline. 
3 137 260 Beyond this they narrow for some distance, then expand greatly. 
4 a pe The abdominal scutes meet along the midline a distance of 
5 165 227 
207 mm.; the femorals, 100 mm.; the anals, 75 mm. 
The pelvis is preserved in position. It has a stout lateral 
pubic process. The tubera ischii are conical, and their apices are 105 mm. apart. 
Testudo osborniana Hay. 
Plates 72-75; text-figs. 552-562. 
Testudo oshorniana, Hay, Ann. N. Y. Acad. Sciences, XVI, 1905, p. 312. 
The type of the present species was secured in 1901, by Mr. Barnum Brown, near the line 
between Colorado and Nebraska, north of Sterling, Colorado. The locality is in the latter 
state. The deposits affording it belong to the Miocene, and are known as the Pawnee Creek 
beds. The specimen belongs to the American Museum of Natural History, and bear its 
catalog number 5868. It consists of a complete shell, the skull (lacking the lower jaw), the 
pelvis, both hinder limbs nearly complete, and the tail. From the deeply concave plastron it 
is concluded that the animal was a male. The total length of the carapace is 775 mm. 
The skull (figs. 552-554) is rather long and narrow a a Testudo, and the ees are moder- 
ately thick and heavy. The sides of the skull are parallel from the squamosal processes to the 
front of the orbits, beyond which they converge with nearly straight outlines to the rounded 
snout. Seen from the side the upper ‘outline of the skull is concave behind the orbits, above 
and in front of them moderately convex. 
The following are some of the dimensions of the type skull: 
Millimeters. Millimeters. 
Snout to the end of the supraoccipital process.. 129 Width of interorbital space : ; 2 
Snout to occipital condyle............. 119 Width of nasal opening transversely... 2 
Width at the base of the quadrates. . . 81 Antero-posterior diameter of the orbit 2 
Width at the hinder end of the maxilla 79 
The height of the skull from the cutting-edge of the maxilla to the upper surface of the 
frontals is contained in the length from the snout to the condyle 2.8 times. 
The prefrontals meet along the midline a distance of 23 mm., and this is also the length of 
the suture between the frontals. The orbits are subquadrilateral. The long axis, 30 mm., is 
directed from the prefrontal border backward, outward, and downward. The jugal arch has a 
width of 16 mm. The maxilla descends from the floor of the orbit a distance of 18 mm. 
The cutting-edge is concave, especially posteriorly, and is rather coarsely dentated. The 
squamosal processes are not laterally comprest, but swollen, especially on the inner side; and 
the outer, upper border rises but little above the upper surface of the paroccipital. 
The antero-posterior extent of the otic region, measuring across the paroccipital and 
prootic, is 33 mm. and contained in the length of the skull to the occipital condyle 3.6 times. 
