336 
MOLLUSCA. 
Family Arcad^e. 
Genus Arca. 
A. Noce, Linn. 
Fine and perfect specimens of the true Arca Noce (according to Mr. 
Alder) are in Mr. Warren’s collection ; they were procured on the coast 
of Cork by Mr. Townsend. 
Arca Noce, Linn. “ One specimen taken in Cork Harbour.” Cork Fauna, 
p. 15 (all said of it). 
A.fusca, Mont. 
“ A single specimen found on the islands called the Calves, so dangerous 
of access, in the West of Ireland.” Turt. Brit. Biv., under the name A. te~ 
tragona. Magilligan, odd valves, W. T. Portrush in situ — Ordnance col- 
lectors. From Kenmare, Co. Kerry, imbedded in stone, Mr. Humphreys, 
in letter, 1809 ; abundant near Castletown, Co. Cork, Mr. Barlee, attached 
to valves of shells on a hard sand-bank at entrance of Birterbuy Bay, 
at a depth of 20 fathoms ; in the fissures of rocks dry at low water in 
Clifden Bay, Dr. Farran. Burrowed in a stone from deep water off the 
Copelands, Sep., 1851, Mr. Hyndman.* 
A. raridentata, Searles Wood. 
A living specimen and a valve of this Arca were dredged from 45 
fathoms off Cape Clear by Mr. M‘Andrew. It is a Crag shell. Mr. M‘An- 
drew procured it alive for the first time off the island of Skye in the sum- 
mer of 1845. 
A. barbata, Brown. 
“ This very perfect and new shell on our coasts was found alive, ad- 
hering to an oyster from Killinchy in Lough Strangford, by Dr. M‘Gee 
of Belfast,” Brown. Never found since. 
Genus Pectunculus. 
P. pilosus, Linn. 
Dublin coast, Br. Turt. More specimens (but all dead) have come under 
my notice on the sandy beach at Magilligan than elsewhere. 
Dredged very sparingly from about 8 to 10 fathoms (sandy ground) in 
Strangford Lough, W. T. ; from several fathoms deeper water at en- 
trance to Belfast Bay, and Glenarm, Mr. Hyndman. “ Two specimens, 
three inches in diameter, were found at Oyster Haven, in 1844,” Mr. J. D. 
Humphreys. 
Genus Nucula. 
N margaritacea, Lam. 
Dublin coast; plentiful, Brown. Common around the coast, grega- 
rious ; dredged at various depths to 50 fathoms (South Rock, Co. Down, 
* A. lactea, Linn. 
This species is noted with a “ ? ” in Turton’s Catalogue as found on the Calves 
Islands. In his Conch. Diet., subsequently published, it is made synonymous 
with A. perforans. 
In shell-sand, deep Avater, Belfast Bay, Mr. Hyndman. 
