313 
where the molluse fauna has been fairly well investi- 
gated, thus also in the Biscaya, off the coasts of the Iberic penin- 
sula, off the Atlantic coasts of North Africa, in the Mediterranean, 
and off the Atlantic coast of the United States N. A. The phe- 
nomenon is so universal that one must hesitate to ex- 
plain it as caused by a sinking of the sea-bed. 
In the ensuing chapter the occurrence of a series of shallow- 
water shells dredged at considerable depths during the deep-sea 
Expeditions ,,Lightning", ,,Porcupine”, ,,Talisman", ,,Travailleur", 
»Fish-Hawk", and ,,Albatross" is to be mentioned. In each case 
the vertical distribution of the living molluscs will be put down as 
exactly as possible. 
In the report on the mollusca frtte: the ,,Lightning" and the 
»Porcupine"-Expeditions J. Gw. Jeffreys does not state, as a rule, 
if his statements of the vertical distribution of the molluses refer 
to living specimens or only to empty shells. By my investigations 
of the molluses from these expeditions in British Museum, Natural 
History, I have, however, been able to substantiate that the state- 
ments very often only refer to empty shells. Proportionally rarely 
the depths at which the molluses have been dredged have appeared 
to Jeffreys:so suspiciously great that he thinks it necessary to add 
a remark to the effect that the shells were dead. His statements 
about the vertical distribution therefore, on the whole, need a revisal. 
Such a revisal for all the species can, however, not be undertaken 
solely by an investigation of the molluses in British Museum, partly 
because a part of the molluses are taken to America, partly because 
Sspecimens of the same species very often are mixed together in the 
same case from vårious stations. The impression is, however, con- 
veyed, by the investigations of these molluses, that British Museum 
to draw attention to his name by publishing in the ,Nachrichtsblatt" 
an extraet of a paper which I have read in ,den naturhistoriske For- 
ening" in Copenhagen, he never sent me any communication. I have 
only heard of it when accidently being told by a friend. 
