EMYDID. 293 
border which joined its fellow of the other side missing, so that it is impossible to determine 
accurately the width of the anterior lip of the plastron. However, this bone has been used 
in making the restoration of the front of the plastron, as seen in fig. 361. Plate 45, fig. 5, and 
text-fig. 362 show this bone as seen from below. It resembles closely the same bone in C. 
guttata, except that its upper side was not so deeply excavated as in the latter species. Accord- 
ing to the restoration the lip had a breadth of about 34 mm. 
The free borders of the epiplastron are subacute. Seen from the side, this border runs 
forward to the gulo-humeral sulcus and then turns rather abruptly downward, forward and 
inward. From the acute edge the bone thickens rapidly, until a thickness of 7 mm. 1s attained. 
The gulo-humeral sulcus probably continued backward on the entoplastron. 
A piece of the thickened border of the xiphiplastron of this specimen is present. It extends 
from the junction with the hyoplastron to just behind the femoro-anal sulcus. Most of the 
free edge is broken away, but enough remains to show that it was acute. It thickens gradually 
until, at the inner border of the surface above, which was covered with horny skin, the thick- 
ness is} mm. The femoro-anal sulcus comes to the free edge 19 mm. behind the anterior end 
of the bone. 
Plate 45, fig. 6, and text-fig. 363 present a view of the first right peripheral, both from above 
and from the right-hand edge, which joined the second peripheral. The left-hand border 
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301. 3034. 33- 365. 
Fics. 361-365.—Clemmys hesperta. Portions of shell. 1. 
361. Left hyoplastron of type. No. 2219 Univ. California. The epiplastron is restored. 
362. Portion of right epiplastron. 1. No. 2179 Univ. California. 
363. First right peripheral, with section (a). <1. No. 2179 Univ. California. 
364. Probable ninth peripheral, with a section (a). No. 2179 Univ. California. 
365. Section of free border of hypoplastron. No. 5527 Uniy. California. 
joined the nuchal. The first peripheral resembles closely that of C. guttata. It will be observed 
that the outer anterior angle of the first vertebral scute extends outward on the bone here 
described and comes into contact with the second marginal scute. We have the same arrange- 
ment here that we find in C. leprosa, as shown by fig. 30, page 102, of Boulenger’s Catalogue 
of Chelonians. This indicates that the first vertebral scute was broader than it is in C. guttata. 
The peripheral mentioned above, probably the ninth of the right side, resembles somewhat 
that represented by plate 45, fig. 7, and text-hg. 364; but it is shorter antero-posteriorly and 
higher, the fore-and-aft dimension being 15 mm., the height 19 mm. The longitudinal sulcus 
runs closer to the upper border than in fig. 364. The figure just referred to presents a view of 
the left ninth peripheral of an individual somewhat larger than the one just described. It 
is part of a lot numbered 552, from either the Mascall or the Rattlesnake beds. Fig. 364 
shows the upper surface and the anterior end of the bone. Accompanying this bone there ts 
the hinder outer angle of the hypoplastron, extending from the suture with the xiphiplastron 
to the inguinal buttress. A view of a section of the bone near the xiphiplastral suture 1s 
