431 
amoDg the many marine shallow-water forms at the above mentioned 
St. 21 (1415 fms.) in the Mediterranean. He adds the following 
note in stating its occurrence; „Two small specimens, which had 
been probably carried out to the sea from a fresh-water river or 
stream and deposited in 1415 fms.“ Trom the Christianiafjord 
Jeffreys records Hydrohia ventrosa and says this aboiit it^): 
„This with several land- and freshwater shells were dredged in 
deep vvater; but they were dead, and had evidently been carried 
into the fiord by streams“. 
In „The Dispersal of Shells“ H. W. Kew^) has given an 
interesting account of the different means by which the shells are 
spread. He mentions that sea-birds are able to spread the Lamelli- 
branchiates which pincli themselves to. the toes of the hirds, and 
that they sometimes, when frightened, may eject the shells from 
the crop. It must however be regarded as granted that sea-birds 
do not transport great masses of shells from the coasts into great 
depths ^). An open question it is, on the contrary, whether or not 
the fishes take an important part in the process of transportation. 
Several authors have exposed their views with regard to the 
shell-spreading by means of fishes. W. H. Dall'^) writes in this 
way: „In the Archibenthai Eegion there is a more or less constant 
V 
drift of debris from the adjacent shallows which gradually forms 
banks of considerable magnitude.A feature in forming certain 
Jeffreys: „Norwegiau Molhisca^. Ann. & Mag. Nat. Hist. Vol. 5. 
1870. 
2) International Sci. Ser. London 1893. 
W. Kobelt supposes (Studien zur Zoogeographie I & II. 1897 & 98) 
that certain molluscs may pass undamaged through the intestinal 
canal of a bird. He writes thus (I. p. 34); „Eine junge Unio oder 
Anodonta, welche von einem solehen Wasservogel unverletzt hinab- 
geschluckt wird, hat alle Chancen auch den Darmcanal unverletzt zu 
passieren^. There is, however, no observation before us to support 
the view of Dr. Kobelt. 
W. H. Dall: „Deep Sea Mollusca and the Conditions under which 
they exist^. Proceedings of the Biological Society of Washington. 
Vol. V. Washington 1890. p. 10—11. 
