178 CARBONICOLA, ANTHRACOMYA, AND NAIADITES. 
from the shell under description. The shale in which A. subparallela occurs is 
lithologically distinct from that in which the other forms are found. 
I had figured two specimens, Pl. XVII, figs. 1 and 2, from the cabinet of 
Mr. Joseph Wright, of Belfast, and remarked at p. 88, ante, that my attention 
had been drawn to the resemblance between this shell and those of the genus 
Anthracomya; and since that time I have been able to study the original specimen 
on which the species was founded, now preserved in the Museum of the Geological 
Survey, Jermyn Street, and some more specimens from Ballycastle in the Belfast 
Museum, two of which have the hinge exposed. This material came into my 
hands after the letterpress of my observations on Anthracomya was printed off, 
but I mentioned the fact that I had come to the conclusion that the shell really 
belonged to that genus in a note on the page of explanation to Pl. XVII. 
I now re-figure the original type by the kind permission of Sir A. Geikie, and 
a specimen showing the greater part of the hinge by the permission of the 
authorities of the Belfast Museum. The hinge, it will be noted, differs from that 
of A. modiolaris in not possessing an elongated posterior lateral tooth, so that this 
character cannot be considered typical of the genus. I have not met with A. sub- 
parallela in the beds at Hollywood, near Belfast, where Modiola Macadamii occurs. 
This species resembles more nearly A. pwnctata than any of the others, but is 
more convex, the lateral constriction is better marked, and the lines of growth 
are somewhat oblique to the long axis of the shell. 
There is a fine slab of this species in the Geological Survey Collection at Dublin 
from Sheve Gullion, Derry, showing a large variety of shells in various stages of 
growth. In the younger shells the oblique sulcus is more marked. 
Baily (‘ Figs. Char. Brit. Foss.,’ 1875) evidently considered all the forms 
described by Portlock as one, for he figures M. subparallela, and in the text 
(p. 114) unites it with Macadami of Portlock and its varieties. 
Keyserling and Hichwald both referred specimens from Russian Carboniferous 
beds to Portlock’s species, but altered the generic name to Cardinia. 
A figure is given by Keyserling (op. sup. cit.), and this differs somewhat in 
contour from Portlock’s type. EHichwald’s description is short, and would do 
for A. subparallela. 
Naiadites modiolaris (p. 131).—To the localities for this shell should be added 
the roof of the 2-foot 9 seam, Galli Colliery, and the roof of the 4-foot seam, 
Bwllfa Colliery, South Wales. 
N. carinata also oceurs in the latter bed. 
