pouring the cruise of the "Michael Sars" in the North 



Atlantic in 1910 only two species of Brachiopoda 

 were taken, both within the limits of distribution pre- 

 viously known. 



Of the Mollusca collected during the expedition the 

 Cephalopoda have been dealt with by professor dr. Chun 

 and the Pteropoda by professor dr. Bonnevie. 



The present paper deals with the Lamellibranchiata 

 (12 species), Scaphopoda (6 species) and Gastropoda (39 

 species), in all 57 species. Three of these are pelagic: 

 Janthina communis, Scyllcea pelaglca and Fiona marina. 

 The other species belong to the bottom-fauna. 



One species, Pholadomya fragilis, is new to science. 

 New to the fauna of Europe are Area profundicola and 

 Mytilimeria flexuosa. The former hitherto known only, 

 from the coast of North America, the latter also from the 

 deep water to the west of the African coasts. In this 

 connection may also be mentioned Hero formosa not 

 hitherto known from Irish waters, and Cassidaria echin- 

 ophora taken off the entrance to the Straits of Gibraltar 

 previously authentically known only from the Mediter- 

 ranean. 



The largest, and incomparably most interesting, part 

 of the collection of Mollusca was obtained from the great 

 depths on the eastern side of the North Atlantic. From 

 lesser depths on that side eleven species were taken at 

 three stations off Ireland (st. 1, 3 and 96), one species, 

 Cassidaria echinophora, from the entrance to Gibraltar 

 Strait (st. 20), and one species, Cymbium proboscidale, 

 from a station off the west coast of Africa (st. 37). 



On the western side of the North Atlantic eight 

 species were taken at two stations (70 and 72) SE of 

 Newfoundland, the first mentioned (70, with seven species, 

 including the one being new to science) situated in very 

 deep water. 



The "Michael Sars" also took a haul with the otter- 

 trawl in the cold area of the Faroe-Shetland Channel (st. 

 102), obtaining six species, all of them characteristic of 

 the depths of the Norwegian Sea. 



During the years 1868 — 70 the "Lightning" and the 

 "Porcupine" explored the seas off the western coasts of 



Europe, from the Faroes and Shetlands to the Mediter- 

 ranean. The collections were dealt with by Jeffreys, 1 ) 

 who showed that the depths of the Atlantic are inhabited 

 by many species of Mollusca known also from the fiords 

 of Norway and from the banks dividing the Atlantic from 

 the Norwegian Sea. Among such species may be men- 

 tioned:— 



Pecten vitreus Limopsis minuta 



Lima excavata Lyonsiella abyssicola 



Lima sarsi Torellia vestita 



Malletia obtusa Troschelia berniciensis, etc. 



He also showed that certain species are characteristic 

 of the atlantic depths, many of them living both in the 

 northern part of the North Atlantic, off the British Isles, 

 and in the southern part, off the Spanish and Portuguese 

 coasts, viz. 



Amiisium lucidum Limopsis aurita 

 Leda pustulosa Dentalium capillosum 



Leda insculpta Calliostoma suturale, etc. 



Malletia cuneata 



Some of these are also found in the great depths of 

 the Mediterranean, but as the "Michael Sars" did not 

 investigate that sea, I need make no further allusion 

 thereto. The "Challenger" Expedition showed that many 

 of the species common to the North Atlantic and the 

 Norwegian Sea occur also near the Azores, and several 

 of them even still farther south (cfr. Edgar A. Smith: 

 Report on the Lamellibranchiata 2 ) and R. Boog Watson: 

 Report on the Scaphopoda and Gastropoda. 3 ) 



During the years 1880—83 the french expeditions of 

 the "Travailleur" and the "Talisman" explored the Bay 

 of Biscay and the waters south of it, as far as Senegal, 

 the Cape Verde Isles and the Sargasso Sea. In 1895 the 

 Bay of Biscay was explored by the "Caudan". Since 1887 



1 ) "On the Mollusca procured during the "Lightning" and "Por- 

 cupine" Expeditions 1868 — 70" in the Proceedings of the Zoological 

 Society of London; part 2 in the volume for 1879, p. 553; part 3, 

 1881, p. 693; part 4, 1881, p. 922; part 5, 1882, p. 656; part 6, 1883, 

 p. 83; part 7, 1884, p. Ill; part 8, 1884, p. 341; part 9, 1885, p. 27. 



2 ) Report Sci. Res. "Challenger", Zool., vol, 13, 1885. 



3 ) Idem, vol. 15, 1886. 



GRIEG — 6 



