212 DUBLIN UNIVERSITY 



shape. Another had one of its radiating ribs surmounted by a double 

 row of the prickly spines. It is still dredged in the bay in the living 

 state. 



Cardium edule (Linneus). 

 Vast numbers of the shells of the common cockle were embedded in 

 the sands of the deposits. One example, found in a raised sea-bed called 

 the Kinnegar, at Holy wood, about 10 feet height above high-water mark, 

 measured an inch and five-eighths in length, and an inch and three- 

 eighths in breadth. It is found abundantly in the living state on both 

 sides of the harbour. 



Cardium Korvegicum (Spengler). 

 I have found a single valve of large size of this species in the depo- 

 sits. I have a fresh, but dead specimen which was thrown up on the 

 strand. I believe living individuals have not been dredged. 



Cardium pygmceum (Donovan). 

 This species, to which Gmelin gave the well-known epithet, Exiguum, 

 but, on account of inadequate definition, lost his claim to precedence, 

 occurred not unfrequently in the beds. It is still met with in a dead 

 state in the bay. 



Lucina horealis (Linneus). 



Shells of this species, the Lucina radula of Lamarck, which Messrs. 

 Forbes and Hanley have discovered to have been previously deter- 

 mined by "the illustrious naturalist of the north," were found in a 

 finely developed state, and in some numbers. The yellowish epider- 

 mis was not entirely decayed. It is still dredged in Belfast Harbour, 

 but not in the living state. 



Lucina flexuosa (Montagu). 

 Fine examples of this delicate species were found in great numbers 

 in the blue clay. They generally measured seven- sixteenths of an inch 

 in length and breadth ; and one individual attained half an inch in 

 length. It is among our present inhabitants of the bay. 



Montacuta ferruginea (Montagu). 

 I have found a single valve of this species in the light-house depo- 

 sits. It does not occur in a living form in the bay. 



