14 Distribution of the Smaller Crustacea. (Sess. 1902-3. 
and probably also in the nostrils of the lythe (or pollack). 
In view of the frequent occurrence of these copepods in the 
nostrils of the cod, it is somewhat curious that they should 
have been so long overlooked. As many as twenty-nine 
specimens have been obtained in the nostrils of a single cod- 
fish, and these comprised males, females (with ovisacs), and 
young in various stages of development. These copepods do 
not seem to be true parasites, but should perhaps rather be 
called commensals, as they appear to live on the mucus which 
the nasal fossee usually contain. Should the copepods, while 
they are alive, be removed from the nostrils of the fish and 
placed in sea-water, they will be seen to swim quite freely, 
which seems to indicate that their habitat in the nostrils of 
fishes is not compulsory, but that they live there from choice, 
and find in the nasal fossee both food and shelter. Two other, 
and apparently undescribed, species of Bomolochus have been 
recently obtained, and are described in Part III. of the latest 
Report of the Fishery Board. One of them, B. onosi, was 
obtained on the inside of the gill-covers of a five-bearded 
rockling from the Firth of Forth; while the other, B. zeugopteri, 
was found adhering to the back of a specimen of Miiller’s 
topknot (Zeugopterus punctatus) from the Firth of Clyde. 
In mentioning these parasitic copepods I have merely 
touched the fringe of a most interesting part of the subject 
of distribution—a part the study of which may yet yield 
important results to those who have time to take it up. 
PRINTED BY WILLIAM BLACKWOOD AND SONS. 
