68 



THE SCOTTISH NATURALIST 



and since that date. I give the numbers of these steam- 

 lining voyages to Rockall, as follows : 



Year. 



igio 

 19II 

 1912 



1913 . 

 1914 



1915 

 I916 



The Rockall fishing has fallen off (not unnaturally) during 

 the last three years, and had already some tendency to do so 

 even before the war. Still, there is nothing in the amount, 

 nature, or locality of the fishing to account for the unusual 

 catch of Trachypterus of which we are speaking, or for the 

 lack of specimens in all the other years. 



VIII. The Horse Mackerel {Caranx trackurus, L.). 



This is one of the many fishes that are doubtless much 

 oftener captured than recorded. Still it is very curious that 

 the only specimens recorded at Aberdeen within the last 

 nine years were all got at one time, though in very different 

 localities, viz., in September 1909, as follows: 



A single specimen was got in the Firth of Forth on 

 31st August 1889, that is to say, precisely at the same season 

 of the year (S.F.B. Rep., viii., p. 357 (1889), 1890). 



Day remarks (i., p. 125) that "they are very uncertain in 

 their migrations," and our experience is a case in point. 



