FRAZER—ON DISTRIBUTION OF ISOCARDIA ALONG THE IRISH COAST. 189 
head by the passage over of the eye of the blind side. In connexion 
with the question as to whether the anomalous position of the front end 
of the dorsal fin in relation to the eyes and the original middle line of 
the top of the whole head, is to be in any way explained by a passage 
forwards of the fin, during development, Professor Traquair exhibited 
a young turbot three-eighths ofan inch in length. This little fish was 
almost perfectly symmetrical, each side retaining its own eye, the right 
one, however, being a very little higher up than its neighbour, and 
the middle line of the top of the head being very shghtly convex 
towards the left side. In this specimen the dorsal fin, though advanced 
on the occipital part of the head, stopped short considerably behind the 
orbital region, while in the adult it 1s known to extend nearly to the 
end of the snout. 
The following communication was then read :— 
On THE DistRIBUTION oF IsocARDIA CoR ALONG THE IRisH Coast, wITH 
ReEcorD oF i1Ts Discovery In Duncarvan Bay sy Joun Goon, 
Esq. By Dr. Wittram Frazer, M. R.I. A., &. 
Owine to the kindness of John Good, Esq., I have obtained, and now 
exhibit, a specimen of Jsocardia cor from the recently discovered 
locality in Dungarvan Bay. I requested Mr. Good to give a brief 
statement of the distribution of this interesting Irish shell along our 
coast, and from his letter the following deductions can be made :——There 
are three principal centres where the Isocardia is now ascertained to 
exist: the north, or Carlingford habit, which is long known—the 
central or Kish Bank, discovered by the late Robert Ball—and the 
southern, Dungarvan Bay, which Mr. Good’s trawlers have explored 
for three or four years past, and where the existence of this shell was 
first ascertained by him. Scattered outliers of these localities afford- 
ing isolated shells are described in works on natural history. Thus, 
to the north, isolated specimens have been dredged so far up as 
Macgilligan, and off the Coplands, at the mouth of Belfast harbour, 
From the central habitat a few scattered individuals have occurred in 
Dublin Bay; and to the south they have been dredged in Cork harbour, 
and even from the entrance to Bantry Bay. Still the shell is rare, and 
its occurrence in its best ascertained localities far from frequent. Thus 
Mr. Good finds that during the trawling season of three or four weeks at 
Dungarvan, about eight or ten specimens are the average number 
obtainable. He says—‘‘ The new locality from which the Oxhorn 
cockle (Lsocardia cor) has been obtained is Dungarvan Bay; depth of 
water, twenty-five fathoms, and clay bottom. Within the last four 
years our Dublin trawlers fished a little closer into the bay than usual, 
and then, for the first time, found the Oxhorn cockle and the Norway 
lobster, the depth of water and the nature of the sea bottom agreeing 
very closely with the northern district, where they have been so long 
known, and where they have a much wider range. At Carlingford I 
VOL. Vv. 2¢ 
