Mollusks. 4101 



side than it did upon the dorsal fin. The line of demarcation between the white and 

 the brown was oblique and waved, but well defined, having little or no shading. The 

 piebald under side of this fish shows that light could have had little influence in form- 

 ing the colouring matter of the skin. — G. Gordon ; Birnie by Elgin, August, 1853. 



Catalogue of Marine Mollusca inhabiting the Dublin Coast. 

 By William White Walpole, Esq. 



I have frequently thought that if a series of local lists of the Mol- 

 lusca of the British seas were published, they would prove quite as 

 interesting and useful for comparison with each other as those of the 

 land and fresh-water species. I have therefore the pleasure of for- 

 warding to you a list of such as I have taken on this interesting coast; 

 — interesting, I say, because there is perhaps no part of the British 

 Islands which can present such a naturally favourable situation for 

 the study of marine Conchology ; since it possesses many extensive 

 strands, strewed with numerous rarities after an easterly gale, besides 

 rich dredging-grounds, such as Dalkey Sound, and the bays of Dublin, 

 Killiney, and Bray. Added to which, our trawlers, who profitably 

 fish the deeper waters off this coast, occasionally bring in species 

 which could not otherwise be obtained except by an expensive course 

 of dredging, which but few conchologists can adopt. I need hardly 

 say that the nomenclature is according to Messrs. Forbes and Hanley's 

 truly valuable work on our Mollusca : those which I have not been 

 able to procure alive, are marked with an asterisk (*). 



Teredo megotara. Killiney Strand, after an easterly gale, Decem- 

 ber, 1849. The wood in which they occurred was pine. 



*Pholas candidus. Merrion Strand. 



* „ crispata. Malahide and Portmamock Strands. 



* „ dactylus. Merrion Strand. 



Xylophaga dorsalis. Trawled in Skerry Bay : I have observed it 

 also in old trawl-beams. 



Saxicava arctica. General. 

 „ rugosa. Common. 



Mya arenaria and truncata. Both common, but difficult to be ob- 

 tained in fine condition. 



Corbula nucleus. General. 



„ rosea. Very rare ; a few have been taken off this coast. 



Sphaenia Binghami. Rare ; inhabiting the thick valves of oyster- 

 shells, Dalkey Sound. 



