452 Rev. Canon Norman's Revision 



LIX. — Revision of British Mollusca. Bv the Rev. Canon 

 A. M. Norman, M.A., D.C.L., F.L.S., &c. 



More than twenty years have passed since my old friend 

 Dr. Gwyn Jeffreys's work — ' British Conchology' — was 

 completed. In the decade which preceded tliat time we had. 

 in company dredged extensively round the British Islands, 

 and especially in the sea east, west, and north of Shetland, 

 down to 170 fathoms, which was the greatest depth at which, 

 up to that time, the sea on our coast had been explored. The 

 new species discovered in these expeditions mainly constituted 

 the additions to our fauna for the first time to be found in the 

 work referred to. 



In 1868 private dredgings began to be greatly surpassed 

 in importance by expeditions undertaken at the expense of 

 our government. The President and Council of the Royal 

 Society were successful in a request made to the Lords 

 of the Admiralty. A scheme for deep-sea dredging was 

 sanctioned, and the surveying-ship ' Lightning ' commis- 

 sioned for the work. In this steamer Drs. Carpenter and 

 Wyville-Thomson explored the sea between Scotland and the 

 Faroe Islands in depths down to 650 fathoms. 



The results were most encouraging, and in the following 

 year (1869) the ' Porcupine' was despatched for more extended 

 operations to the south and west of Ireland and north of Scot- 

 land. The work of this year was a complete success, and 

 discoveries were made, both physical and biological, of the 

 highest value. Dredgings were carried down to 2435 fathoms. 

 Drs. Carpenter, Jeffreys, and Wyville-Thomson were the 

 scientific men in charge during these cruises. 



The next important work which threw light upon the 

 British marine fauna w T as that done by H.M.'s hired ship 

 1 Knight Errant,' under the direction of Dr. John Murray, in 

 the neighbourhood of the " Wyville-Thomson Ridge " in 

 1880. 



In 1882 the government ordered the ' Triton,' a composite 

 steamship of 410 tons, to resurvey and more thoroughly 

 explore the remarkable geographical features connected with 

 the sea-bottom on either side of the lt Wyville-Thomson 

 Ridge." Dr. John Murray had again the scientific direction 

 in this expedition. 



Last year (1889) a short dredging trip in deep water off 

 the south of Ireland by H.M.S. ' Research ' was superintended 

 by Mr. G. C. Bourne, the Director of the Marine Biological 



