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DR. GWYN JEFFREYS ON THE MOLLUSCA OF [June 19, 



In 1869 succeeded the Expedition in the Surveying steam-ship 

 •Porcupine;' and the third cruise in that year was devoted to 

 the further examination of the "Faroe Channel." The Mollusca 

 obtained during this cruise did not show so great a difference be- 

 tween the "warm " and "cold" areas as appeared to be the case in 

 other departments of the Invertebrata. 



During the following ten years took place the further and more 

 extended cruises of the 'Porcupine,' and the Expeditions in H.M.S. 

 ' Valorous ' and * Challenger,' all of which originated in the first 

 mentioned cruise of the ' Lightning.' 



In 1880, previous to the lamented death of Sir Wyville Thomson, 

 the Government was induced on his application to grant the use of 

 a hired ship, the 'Knight Errant,' for the reexamination of the 

 Faroe Channel. The vessel was small and the weather bad ; but 

 some results were obtained, and communicated by Mr. John Murray, 

 the naturalist in charge, to the Royal Society of Edinburgh, who 

 published the account in their ' Proceedings.' I contributed a list of 

 the Mollusca. Staff-Commander Tizard conducted this cruise as 

 well as that in H.M.S. ' Triton ' ; he had been one of the officers in 

 the ' Challengef- ' Expedition. Mr. Murray was one of the natura- 

 lists on board the ' Challenger,' and is well known for his admirable 

 work on deep-sea deposits. 



In 1882 the Government ordered the 'Triton,' a composite steam- 

 ship of 410 tons, which was employed in the Surveying service, to 

 resurvey and explore the sea-bed lying between 59 and 61 degrees 

 of North Latitude, and especially the " Wyville-Thomson ridge," 

 which was supposed to separate the "warm" from the "cold" 

 area. Mr. Murray had also the scientific charge of this short cruise. 

 It was made in August. The weather was, on this occasion also, 

 bad ; but the results as regards the Mollusca were most interesting, 

 and include the discovery of several undescribed species. 



The following is a list of the Stations with other particulars : — 



' Partly on the ridge. 



^ The trawl had been carried right over the ridge and came up in the Cold 



