(Plate S continued.) 
anterior surface of which are preservetl the vascular markings 
which by branching and uniting form a network that is unique 
among brachiopods. To the right of the median septum, two of 
these markings are seen passing into the ridges which occur 
typically on the mold, the impressions of the vascular sinuses. 
The impression of the brachial platform, hinge plate, the filling 
of the spondylium, and pedicle opening are also shown. Natural 
size. 
Ca m a rophoreUa len ticu la ris. 
Fig. 34. Brachial view of one of the type specimens in the American museum 
of natural history, New York City. Introduced to show the 
identity of structure in the platforms. The filling beneath the 
platform of the brachial valve is broken away exposing it; the 
hinge plate and filling of the spondyliimi are also shown. Kin- 
derhook beds, Burlington, Iowa. X 2. 
Camarophorella mutabilis. 
Fig. 35. Lateral view of a .specimen showing the median septum and spondy- 
lium of the pedicle valve. Natural size. 
Fig. 36. View of a portion of the surface enlarged. X 10. 
Figs. 37, 38. Two views of the interior of the pedicle valve showing the 
spondylium and median septum. In figure 37 the position of 
the pedicle opening is indicated and the median narrow tongue- 
shaped scar of the adductor muscle. The concavity of this 
spondylium is less than normal. The thickness of the valve, as 
represented in both figures, is too great. X 2. 
Fig. 39. Interior of beaks of a large specimen showing the broken spondylium, 
a, and detail of the hinge line, the broken median septum of the 
brachial valve, e, hinge plate, b, and bases of the crura, d. On 
the brachial platform, c, the secondary lateral septa are well 
developed. X 2. 
Figs. 40, 41. Interior of the beak of a young specimen in which the structures 
of both valves are preserved, showing the spondylium and its 
supporting median septum, the position of the pedicle opening, 
the high median septum of the brachial valve, the brachial plat- 
form and hinge plate with the bases of the crura. The septum 
extends above the hinge plate stronger than usual. X 2. 
Figs. 42, 43. Two views of the interior of the beaks of a moderately large 
specimen showing a spondylium more concave than that shown 
in figures 37 and 38. The scar of the adductor muscles is indicated 
in figure 42. The details of the hinge and the crura with their 
flattened, scarred tips are well shown. The accessory plates 
between the spondylium and inner surface of the valve, h, are 
visible, better developed than is usual in such a late stage. X 2. 
