CAMAROPHORIA. 141 
I am, therefore, inclined to follow Davidson in regarding it as distinct from 
both these species. 
Rh. bijugata, Schnur, only differs in being a rather larger shell, and appears to 
be identical. 
5. CamaropHoria Puiiuipsi, Davidson, sp. Pl. XVI, figs. 1, 1a, 1), 2, 2a. 
1882. RuyncnoneLtta Puriiipsit1, Davidson. Brit. Foss. Brach., vol. v, pt. 1, 
p. 43, pl. u, fig. 14. 
Localities—From Lummaton I have eight specimens, as well as eighteen 
smaller flat shells which I believe to be the young of this species. There are two 
specimens in the Woodwardian Museum, and one in the Torquay Museum. 
There is a specimen from Wolborough in the 'Torquay Museum, and another in 
the Museum of Practical Geology. 
Remarks.—I1 believe this may be regarded as a well-established species. 
Comparing my larger specimens (some of which I formerly regarded as Kh. 
reniformis, from their likeness to the shell figured by Davidson in his vol. iu, 
pt. 6, pl. xii, fig. 6), they appear to have a general specific resemblance though 
showing considerable variatién in detail. The ribs on the median fold are either 
four or five, though in one instance, at least, they are reduced to two by partial 
amalgamation. ‘The shell is sometimes considerably transverse. The straightness 
of the median dorsal contour, and the presence of rather indistinct lateral ribs, as 
well as other features, distinguish it from Rh. pugnus and Rh. reniformis 
respectively. Its transverseness and its less elongated central part distinguish it 
from Rh. protracta. 
More common than the larger form is a small, flat, subtriangular, wedge- 
shaped shell, with little or no fold or sinus, but with four or five low, round, 
close ribs on the central part, while the lateral parts are smooth. The beaks are 
more erect, and the hinge part of the margins straighter; but these points seem 
probably due to age, and in some of the specimens there are indications of a 
low angular fold. These evidently all belong to one species, and are of such a 
shape as might naturally be expected in the young form, while some specimens 
come midway between, so that it is not easy to assign them to either group. At 
the same time it is to be noted that one of my shells, which presents all the 
characters of the adult, is as small as any of the wedge-shaped form. These 
young shells, it is true, closely resemble one of Davidson’s figures of the young of 
Lh. acuminata ; but I cannot trace any link between them and Devonian specimens 
of the latter shell. Moreover, within the beak (both of the young and adult 
