148 Dr. GC. W. Andrews on 
grooves marking the limits of the epidermal shields are 
rather faintly marked; this is especially noticeable on the 
plastron. 
The plastron (fig. 2) is nearly completely preserved, wanting 
only a part of the right epiplastral and the extremities of the 
xiphiplastrals. The latter loss is unfortunate, because it makes 
it impossible to be sure whether the posterior end of the 
plastron was notched as in Pleurosternum, but I believe that 
Sat, 
PS ce. aN 
SSD att 
eee 
Ayp.p ? _ gee rete, 
< 
m4, 
ae ee. 
al : At 
as the 
Tholemys passmorei, gen.etsp.u. Diagram of ventral aspect of plastron. 
< nat. size. 
abd., abdominal shield; av., anal shield; Ent., entoplastron; Ep., epi- 
plastra; g., gular shield; %., humeral shield; Hy.p., hyo- 
plastron; Hyp.p., hypoplastra; ¢g., mtergular shield; «@m., 
inframarginal shields ; pect., pectoral shield; Xz.p., xiphiplastron. 
it was not. The length of the plastron is approximately 
310 mm., the length of the bridge 132 mm., the width of the 
anterior lobe at its middle point 125 mm. The hyo- and 
hypoplastral buttresses are strongly developed, especially the 
latter; their points of attachment to the carapace have been 
noticed above. ‘There seems to have been no central vacuity 
in the plastron. 
