Chaetognatha collected by the "Tjalfe" Expedition 
to the west coast of Greenland in 1908 and 1909. 
By 
Paul L. Kramp. 
The Tjalfe" Expedition to the west coast of Greenland in 
1908 and 1909 was carried out with regard to practical fishery- 
investigations. At the same time, however, the leader of the ex- 
pedition, cand. mag. Ad. S. Jensen, preserved a considerable and 
very interesting material of marine invertebrates. Several hauls 
were made with instruments for pelagical fishing (plankton-net, ring- 
trawl, and Petersen's young-fish trawl) in order to study the occur- 
rTence and distribution of pelagic fish eggs and larvæ. By these 
pelagic hauls a very large number of chaetognaths were brought 
up. It was impracticable to preserve the whole lot, but from the 
part of the material brought home we are able to form a concep- 
tion of the occurrence of these animals in the waters of Green- 
land. In the journal of the expedition chaetognaths are recorded 
from 96 pelagic hauls; in 39 cases the material was preserved. 
Ås a rule all of the individuals of a sample were preserved; when 
only a part of them were kept, this was noted in the journal. 
Most of the material was preserved in alcohol. This method 
is not suitable for chaetognaths; it causes a considerable contrac- 
tion of the muscles, so that reliable measurings are impracticable; 
the tissues become opaque, and frequently the interior of the ani- 
mal is filled up by a turbid mass; this may be removed by clearing 
in xylol, but in several cases the genital organs, particularly the 
testes, are more or less destructed, so that it is impossible to de- 
fine the state of maturity. If the glass has contained a large number 
of individuals, these are soft and breakable and must be handled 
With great care to be kept uninjured. 
Vidensk. Medd. fra Dansk naturhist. Foren. Bd. 69. 2 
