38 Professor King on certain Species of Permian Shells 
DIELASMA SUFFLATA—T'erebratulites sufflatus,* Schlotheim. ~ 
In my Monograph (1850), it is stated that this species “ ap- 
pears to be identical with a shell found in the mountain-lime- 
stone of Bolland, probably hitherto considered a variety of D. 
sacculus—a distinct, though closely allied species. The latter 
differs from the former principally in having the front decidedly 
emarginate; both appear to graduate into each other” (p. 150). 
Referring to this same species in the Introduction to the work 
cited, I state that it ‘“‘ undoubtedly lived in the Carboniferous 
epoch” (p. xxi.); and in my “ Notes on Permian Fossils— 
Palliobranchiata” (Annals of Natural History, April, 1856), 
the following remarks occur :—“ I have been led to re-examine 
the ‘shell found in the mountain-limestone of Bolland,’ and I 
cannot but say that it agrees most remarkably with some 
specimens of the Permian species, particularly the testiferous 
one represented under figure 7, plate vii. of my ‘ Monograph.’ 
On the other hand, there are specimens figured on the same 
plate closely approximating to true forms of D. sacculus in its 
mesial depression and emarginate front. The only difference — 
I perceive between the Bolland shell alluded to, and the Per- 
mian fossil quoted, is, that on the former there are faint traces 
of a few longitudinal lines on the anterior half of the valves. 
I perceive nothing of the kind on any of the Permian forms, 
nor do I recognise any on normal specimens of D. sacculus. 
There appears to be no difference between them in their histo- 
logical perforations.” 
On referring to Mr Davidson’s remarks on Dielasma 
suflata in his “ Monograph of British Permian Brachiopoda,” 
which contains all his published observations on the subject, I 
do not find anything more than the above passages (which he 
has fully acknowledged by reproducing them) calculated to 
prove that the Permian species is identical with the Carboni- 
ferous D. sacculus. Nay, it would appear that he considers 
* The allied Permian species, Terebratulites elongatus, Schlotheim, forms the 
type of the genus Dielasma, so named at first in my “ Historical Account of the 
Invertebrata occurring in the Permian Rocks of the North of England.”—. 
Effingham Wilson, 1859 ; and afterwards described in a paper which was read 
before the Dublin University Zoological and Botanical Association.— Vide 
“ Natural History Review,” vol. i. 
