SEA-FISIIERIES LABORATORY. 245 



which may, if not corrected, give rise to a false 

 impression. The Marine Biological Association obtain 

 gatherings once a fortnight from certain light-ships on 

 the west coast, and one of these (on the Bahama Bank) is 

 in our district of the Irish Sea. On the basis of these 

 fortnightly gatherings (23) at this one station, in the 

 year (1904) under discussion, Dr. L. H. Gough states in 

 the official Blue-book that 4k Ceratium tripos was never 

 seen at Bahama Bank," and again, '-' In the Irish Sea it 

 [C tripos] was rarest or even absent at the northern 

 stations " [that is at the Isle of Man]. From such state- 

 ments one would certainly gather that the organism in 

 question was very rare, if not altogether absent from our 

 district ; but the fact is that it occurs practically all the 

 year round in considerable abundance off the Isle of Man. 

 Ceratium tripos is regarded as an oceanic species, and it 

 is stated to have been found " very frequently " at 

 Plymouth throughout 1904, but as no numbers are given 

 in the detailed tables of the Blue-book (but merely crosses 

 which indicate the presence, or in some cases letters to 

 indicate relative abundance), it is impossible to compare 

 results and to say whether our recorded figures for the 

 Irish Sea are greater or less than the numbers of this 

 organism found in the English Channel. And yet from 

 the fortnightly gatherings from certain light-ships (one 

 of which is in our district), in which certain organisms 

 were not found, the far-reaching conclusion is drawn that 

 " on the whole the Irish Sea may be said to be more 

 neritic [i.e., showing a scarcity of oceanic species] than 

 the Channel" (p. 169). That may be the case, but the 

 conclusion can scarcely be based upon such statistics as the 

 North Sea Fisheries Investigation Committee put forth in 

 their official Blue-book. The facts in regard to this 

 " oceanic " species Ceratium tripos are : — 



