ON DREDGING THE COAST OF ABERDEENSHIRE. 143 



found to be 65 fathoms, and the bottom mud. Round this spot the dredging 

 was carried on for the day. During the afternoon a breeze sprang up, and 

 the working of the dredges became impossible. There was nothing for the 

 Committee but to return to Peterhead Bay. 



The portion of the coast explored extends from Girdleness, the southern 

 extremity of Aberdeenshire, to a few miles north of Peterhead. There thus 

 remains -undredged a distance of rather more than ten miles on the east 

 coast, and of twelve miles on the north coast, at the entrance of the Moray 

 Firth, from Kinnaird to the Banffshire coast. The Committee regret that the 

 weather was not more favourable, as they have every reason to think they 

 would have been able to accomplish the dredging of the whole of the Aber- 

 deenshire coast, 4 and thus have had the means of presenting to the Association 

 a much fuller report than the one now submitted. 



From the soundings, and the nature of the dredgings, the following con- 

 clusions may be drawn : — The sea gradually deepens for a distance of eight 

 to fifteen miles, when a bank covered with Arctic fossil shells occurs. The 

 depth again goes on increasing, till the bank called " The Long Forties " is 

 reached. From this bank no Arctic fossil shells were obtained but decayed 

 littoral species. The inner bank is, no doubt, composed of drift. It is 

 highly probable that the outer bank (" The Long Forties ") was at one period 

 an island, or the shore of a continent, which has since been submerged under 

 the sea. 



It may be remarked that, along with the littoral species dredged from 

 " The Long Forties," there came up a valve of the "West Indian shell, Lucina 

 pemylvanica . 



On referring to the Report of the Committee for dredging the North and 

 East Coasts of Scotland, laid before the meeting of the Association in 1862, 

 it will be found that the number of Mollusca collected by Mr. Dawson on the 

 Aberdeenshire coast amounted to 223 species, arranged as follows : — 



Gasteropoda Prosobranchiata 110 



Opisthobranchiata 11 



Nudibranchiata 8 



Pteropoda 1 



Conchifera Lamellibranchiata 92 



Brachiopoda 1 



223 



Since that time 36 species have been added to the list, arranged as 

 follows : — 



Gasteropoda Prosobranchiata 14 



Opisthobranchiata 1 



Nudibranciata 14 



Pteropoda 



Conchifera Lamellibranchiata 5 



Brachiopoda 2 



"36 

 Formerly found 223 



Making in all 259 species. 



The most interesting of the newly added species are Cerithiopsis tubercu- 

 laris (2 specimens), Mangelia laevigata, var. (1 specimen), Buccinopsis Dalei 

 (1 specimen), Troehus Grcenlandicus (1 specimen), Fusus propinqims (several 

 specimens), Odostomia pallida (1 specimen), Propilidium ancyloides, Am- 



