184 THE DEPTHS OF THE SEA, [CHAP. IV. 
The northern species above referred to are 34 in num- 
ber, and include Dacridium vitreum, Nucula pumila, 
Leda lucida, L. frigida, Verticordia abyssicola, Neewra 
jugosa, N. obesa, Tectura fulva, Fissurisepta papillosa, 
Torellia vestita, Pleurotoma turricula, Admete viridula, 
Cylichna alba, Cylichna ovata, JEFFREYS n. sp., Bulla 
conulus, 8. Woop not DrEsHayes (Coralline Crag), 
and Scaphander librarius. Leda lucida, Newra 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 
wells 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 Melam- 
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 
