only on the same fish have been found all the developmental stages 
which precede that of insertion into the body of the host. As 
already mentioned I have examined a great number of Scopelini 
and allied forms from the Atlantic, between 2 and 3 thousand spe- 
cimens, but I have never found this parasite — nor any other Para- 
sitic Copepod — on other species of the genus Scopelus (taken in 
its widest sense as comprising Bhinoscopelus, Myctophum etc.) nor 
on species of genera like Cyclothone, Argyropelecus, Maurolicus, 
Stomias etc., which were captured by the ”"Thor” often in numbers 
together with Scop. glacialis on the same stations. The parasite in 
question has only been taken by the Thor” in the part of the 
Atlantic lying between 48? 15' Lat. N. and 65? Lat. N., and between 
4 33' Long. W. and 28? 10' Long. W., always in a considerable 
depth — from 100 to 600 met. below the surface. By the ship 
Tjalfe”, on a surveying expedition to the Greenland waters under 
Supervision of Mr. Ad. Jensen, only åa single (young) specimen 
was captured farther west, sc. at 487267 Long. W., 60? 07' Lat. N. 
In the Davis-Strait it seems not to occur; among some 330 speci- 
mens of Scop. glacialis collected by the "Tjalfe" W. of Greenland, 
between ca. 63” and 719 Lat. N., none were found infested. In 
collections made by the ""Thor” in the Atlantic south of the above 
named boundary I did not find the parasite; and it is likewise 
wanting on the numerous Scop. glacialis collected by the Thor” 
in the Mediterranean. In the latter this fish and — less often — 
two other species of Scopelus were found infested with an allied 
Parasitic Copepod Peroderma bellottii; but on this I never found 
åny Hydroid. 
That our parasite is by no means of frequent occurrence 
Seems to be proved by the fact that to yield the 22 above-named 
specimens more than 1800 specimens of Scopelus glacialis had to 
be examined. 
For the sake of completeness all the localities for the material 
examined are given below. 
beg 
