414 
has secured all the more important and iuteresting findings from 
these expeditioiis. It is, in faet, my conviction that if a species 
has heen recorded from an unusnal great depth from the „Light- 
ning‘‘ or the „Porcupine“, and if there in the Museum is nothing 
to refer the statement to, there is at anj rate, no question about 
living specimens, but the statement has onlj reference to dead shells 
or probably very often to mere fragments. 
In the following it will be mentioned that the „Lightning“ 
and the „Porcupine“ Expeditions have, procured a great deal of 
dead shells that surely (or in some cases presumably) have lain 
outside the vertical range of the corresponding species. The depth 
at which the shells have been dredged is quoted from Jeffreys 
and put down in one of the columns. To make a comparison the 
vertical range of the living molluscs has been stated in other colums. 
The named species are, as a rule, common forms whose vertical 
range may not be supposed to be quite unknown. As to the 
statements of the vertical distribution of the species in the At¬ 
lantic I have essentially relied on various English authors, who 
have distinguished between the living molluscs and the dead shells 
in stating the vertical distribution, and on the collections in British 
Museum, Natural History. If to the statement of depth B. M. is 
added, it means that the recorded maximum depth is the greatest 
from which I have found recent specimens in the Museum. With 
regard to the forms that have been dredged between the Færoe- 
Isles and the Channel I have also added the vertical distribution 
of the species at the coasts of Norvvay, in the Skagerrack, and in 
the Kattegat, from G. O. Sars „Mollusca regionis arcticæ“ etc. 1878, 
C. G. Joh. Petersen (1893) ^), A. Norman 1. c. 1893), J. Sparre 
Schneider (1885 — 86)^), James A.Grieg (l.c. 1896—97), James 
A. Grieg & Friele (1. c. 1901). This has been done mainly because 
^) C. G. Joh. Petersen: „Mollusca^. „Hauchs^ Togter. Kjøbenhavn 
1893. 
J. Sparre Schneider: „Tromsø Sundets Molluskfauna‘‘. Tromsø 
Museums Aarshefter 8—9. 1885—1886. 
