HYDE: CAMAROPHORELLA. 51 
sometimes remarkably. The fimbriae are usually most abundant 
and longest near the ventral end, especially about the point of separa- 
tion of the lamellae. This is somewhat in contrast to the fimbriae 
of the lamellae of the cones which are always best developed toward 
the opening of the valves. In further contrast, the fimbriae occurring 
on the large lamellae of the cones are always situated on the side of 
the ribbon toward the base of the cone. On the lamellae of the jugum 
they are located on the opposite sides of the ribbon, the ones directed 
toward the apices of the cones. As in the larger lamellae they are 
situated marginally or submarginally and are always directed outward. 
Rarely a spine or two occurs on the margin of the anterior plate of the 
jugum, also directed outward (pi. 9, fig. 45). 
Inner surface of the valves. — The inner surfaces of the valves are 
marked by radiating furrow-like vascular sinuses which usually appear 
on the molds as more or less distinct ridges. They do not appear as 
the usual, very delicate vascular impressions except in one specimen, 
(pi. 8, fig. 33), on the anterior half of which, each sinus is represented 
by a very delicate double ridge in the mold, and several of them can be 
traced into the more pronounced ridges on the posterior half, which 
are more typical of this genus. In most cases the ridges extend from 
the region of the beaks to the anterior periphery, sometimes becoming 
indistinct as they approach the margins. They are often intermittent; 
the crest (in the mold) is sometimes divided by a small median furrow, 
and they rarely bifurcate. Figures 21 and 28 (pi. 8) show the usual 
method of occurrence. The vascular sinuses can be traced into the 
beaks and under the platforms of both valves where they gradually 
disappear without any indication that they were connected with a 
central canal. 
In the one specimen referred to above which differs from this, the 
method of occurrence of the sinuses on the anterior half is not only 
unusual for this species, but is anomalous in the class Brachiopoda, 
in that they bifurcate freely and reunite with each other, forming a 
network of sinuses. It appears from an examination of published 
draAvings of brachiopods that in those types in which the canals branch 
freely, one may occasionally unite with another, but such a network 
as is here found is elsewhere unknown to the writer. 
In addition, the inner surface of both valves is usually covered with 
small sharp pits which give the mold a pustulose appearance. 
