134 THE DEPTHS OF TBB SBA. [chap. iv. 



The northern species above referred to are 84 in num- 

 ber, and include Bacridium viireum. Nucula pumila, 

 Leda lucida, L. frigida, Verticordia abyssicola, Necera 

 jugosa,N. obesa, Tectura fulva, Fissurisepta papillosa, 

 Torellia vestita,Pleurotoma turricula, Admete viridula, 

 Cylichna alba, Cylichna ovata, Jeppkeys n. sp., Bulla 

 Gonulus, S. Wood not Dbshayes (Coralline Crag), 

 and Scaphander Ubrarius. Leda lucida, 'N emra jugosa, 

 Tectura fulva, Fissurisepta papillosa, Torellia vestita, 

 as well as several other known species in this dredging, 

 are also fossil in Sicily. Nearly all these shells, as 

 well as a few small echinoderms, corals, and other 

 organisms, had evidently been transported by some 

 current to the spot where they were found ; and they 

 must have formed a thick deposit similar to those of 

 which many tertiary fossiliferous strata are composed. 

 It seemed probable also that the deposit was partly 

 caused by tidal action, because a fragment of Melain- 

 pus myosotis (a littoral pulmonibranch) was mixed 

 with deep-water and oceanic Pectinibranchiates and 

 Lamellibranchiates. None of the shells were Miocene 

 or of an older period. 



"This remarkable collection, of which not much 

 more than one-half is known to conchologists, not- 

 withstanding their assiduous labours, teaches us how 

 much remains to be done before we can assume that 

 the record of Marine Zoology is complete. Let us 

 compare the vast expanse of the sea-bed in the North 

 Atlantic with that small fringe of the coast on both 

 sides of it which has yet been partially explored, and 

 consider with reference to the dredging last men- 

 tioned what are the prospects of our ever becoming 

 acquainted with all the inhabitants of the deep 



