KING—ON PALLIOBRANCHIATE SHELLS. 173 
This species agrees with Discina lamellosa (Broderip) in having a 
nearly circular margin and a sub-central apex, but completely differs 
therefrom in the character of its external ornamentation; and the la- 
mellz, which distinguish the latter shell, cannot be identified with the 
raised lines of Discina Atlantica. Mr. J. Gwyn Jeffreys, who has seen 
the specimen, has suggested that it may be a young example of Discina 
tenuis (G. B. Sowerby)—a suggestion not supported by the representa- 
tions of this species in the ‘‘ Thesaurus Conchyliorum.”’* Although 
appearing to agree with Discina Atlantica in being finely striated con- 
centrically, Discina tenuis has a less circular marginal outline, and its 
apex (stated to be ‘‘ near the posterior margin’’) is decidedly sub-mar- 
inal. 
‘ A rare British fossil shell has been made known, which, on account 
of its geographical station, requires to be noticed in connexion with the 
present species—I allude to the specimen of a Discina found thirty 
years ago, by Mr. Searles Wood, in the ‘‘Coralline Crag,’’ at Sutton, 
in Suffolk, and noticed by him, under the name of ‘“‘ Disciona Norve- 
gica?’”’ in his ‘‘ Catalogue of Shells from the Crag.’’} The specimen, 
like the one I have described, is ‘‘only one valve, and that imper- 
fect.” It is now in the British Museum, having been presented to 
the national collection by Mr. 8. Wood, along with his highly valu- 
able series of Crag Fossils. Mr. Davidson has given figures and a de- 
scription of the Sutton specimen, and named it ‘‘? Orbicula lamellosa.’’t 
At one time I entertained a suspicion that the shell herein described 
might turn out to be specifically identical with the Crag specimen; but 
having lately examined the latter in the British Museum, through the 
kindness of Dr. Baird, I find that the present species has a more cir- 
cular form, seemingly finer lines of growth, also a more elevated and 
less excentrically situated apex. 
Mr. James Haughton, Jun., exhibited some shells of Lanthina fragilis, 
‘‘common ocean shell,” taken by him last summer in great quantities 
on the Wexford coast; he also showed some specimens given to him 
some years ago by the late Professor Kinahan, which, however, were 
considerably smaller than those now shown as lately taken by him- 
self. He had had them alive for some days, in a bowl of sea water, 
and thus had had an opportunity to see their curious float. He lost 
them shortly, however, apparently owing to the water becoming foul, 
from the dense purple excretion given out by these animals. 
Mr. Adair mentioned having once, some twenty years back, taken 
this shell in immense quantities on the Antrim coast, and was disposed 
to think its occurrence on British coasts to be periodical. 
* Pl. lxxiii., Figs. 4 & 5, op. cit. 
+ Published in the ‘‘ Ann. and Mag. of Nat. Hist.,” vol. vi., p. 155-184. 
t See “ Fossil Brachiopoda of Great Britain,’ Part I., p. 7, Pl. 1, Figs. 9, 9a, 96. 
VOL. V. Dd fe 
