204 DUBLIN UNIVERSITY 



from much deeper levels, which may be estimated from the fact that 

 vessels drawing ten feet at low water, and eighteen feet at high water, 

 can by this means now easily reach the town. It affords an example 

 of the importance of seizing opportunities for prosecuting scientific re- 

 searches, presented by the progress of altogether different operations, 

 when we consider that these localities will never again be accessible 

 to inspection, the channel being now occupied with water, and the 

 railways completed and ballasted over. The deposits appeared to have 

 the shells rather scattered everywhere throughout them than lying in 

 regular beds. This, together with the fact that the same shells were 

 found at almost every depth, made it useless as well as impossible to 

 observe levels to which the species should respectively belong. Be- 

 sides, the shells, no matter at what depth found, were all of recent 

 species. Thus the whole formation appears to be of one geological age. 

 In addition to those localities, may be mentioned the foundations of the 

 town generally. 



The order and nomenclature I shall use are those which appear in 

 Professor Forbes' and Mr. Hanley's " History of British Mollusca." 



Teredo Norvegica (Spengler). 

 Of this species, which was so long confounded with the Teredo 

 navalis of Linneus, but the merit of whose restoration to its original 

 distinctness is due to Messrs. Forbes and Hanley, three portions of 

 tubes have been met with by myself. They were merely embedded in 

 the clay, as if the wood in which their inhabitants had pursued their 

 operations had decayed away from about them ; and since the valves 

 were not found, and the tubes were only fragmentary, they had expe- 

 rienced the mercies of currents and waves. Their presence in the 

 deposits appears to me corroborative of the evidence adduced to prove 

 the indigenousness of the species, in opposition to the prevalent opinion 

 among British naturalists, since it is not likely that at the period of 

 their existence, Belfast, which is a town of extremely modern growth, 

 was at all visited by foreign ships. Two of the fragments bore the dis- 

 tinctive semi-concameration of the species, and were, therefore, from 

 the narrow end of the tube; one of them being three inches in length 

 and half an inch in diameter at the widest part, while the third had 

 attained the maximum breadth of three-fifths of an inch. They were 

 covered with the remains of that olivaceous epidermis which is more 



