Hyde. — Camarophorella. 
PLATE S. 
Camarophorella mutabilis. 
Figs. IS, 19, 20, 22. Brachial, pedicle, lateral, and anterior views respectively 
of a moderate-sized specimen thicker than usual, in which a con- 
siderable portion of the original shell is preserved, showing the 
inconspicuous fold and sinus, the depressed furrow extending 
the length of both valves, and small areas of the internal mold 
showing the vascular sinuses and pitted surface. Xote the slight 
as\^llmetr\' of the depressed median furrow. The pedicle open- 
ing is poorly shown and the beak is more incurved than usual. 
Natural size. 
Figs. 21, 24, 25. Brachial, lateral, and anterior views respectively of a mod- 
erately large internal mold of normal thickness selected as the 
tj-pe of the species, showing slight fold and sinus, lenticular 
shape, and radiating vascular sinuses extending to the anterior 
margin of the shell. In figure 21 the position of the median sep- 
tum of the brachial valve is shown and the filling of the ca\'ity 
between the shell and the brachial platform is partly broken away 
exposing the platform, c, divided into two parts by the septum. 
Immediately posterior to this. platform is seen the mold of the 
hinge plate, b, and just behind it the filling of the spondylium of 
the pedicle valve, a. Natural size. 
Figs. 23, 2S. Brachial and anterior views of an internal mold of a large, 
asymmetrical specimen, showing the subpentagonal outline and 
more pronounced fold and sinus which are usually found in older 
individuals, also the radiating vascular sinuses. Natural size. 
Figs. 26, 27. Brachial and lateral views of a gutta-percha cast taken from 
a mold of the exterior of a moderate-sized specimen, showing the 
slightly inciu-ved beak, terminal pedicle opening, and deltidial 
plates, very slight fold and median depressed furrow. Natural 
size. 
Figs. 29, 30. Pedicle and anterior views of a gutta-percha cast takefi from 
a mold of the exterior. This is the smallest specimen seen and 
shows the absence of both fold and sinus but distinctly the pres- 
ence of the median furrows which appear at a verj' early stage. 
Natural size. 
Figs. 31, 32. Brachial and anterior views of an internal mold of a larger 
specimen .showing the absence of fold and sinus and the presence 
of the median furrows. The brachial platform is exposed by the 
breaking away of the filling between it and the shell, also the 
spondylium. Natural size. 
Fig. 33. Brachial view of the mold of a moderately large specimen, on the 
