256 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



occurrence in previous years in the open sea in January 

 and February (Lane. Sea Fisheries Laby. Beport, No. XIV, 

 1905, p. 85) ; and Mr. I. C. Thompson recorded an immense 

 shoal between Douglas and Port Erin in May, 1888 (L'roc. 

 L. Biol. S., Vol. in, p. 188). 



PSEUDOCALANUS. 



It has seemed advisable to take out separately the 

 distribution of the Copepod Pseudocalanus elongatus, 

 which is present and fairly abundant throughout the 

 year. It is represented in almost every gathering, and 

 by high numbers (for a Copepod) in nearly every month. 

 The greatest quantity for a single net rises in April to 

 over 8,000 more than once, and in August reaches 16,000. 

 But the maximum is seen from August 29th to September 

 18th, when the following very high numbers occur, with 

 occasional lower ones between them: — 23,000, 86,000, 

 21,000, 38,600, 15,000, 12,000, 11,000, 25,000, 12,800— 

 each of these being the catch in a single net. These are, 

 of course, the picked highest numbers of the year, and 

 they all happen to represent hauls of the weighted open 

 tow-net, which indicates that this species of Copepod is 

 in greatest abundance a few T fathoms below the surface. 

 Quite apart from the exceptional hauls quoted above, we 

 find that neither the surface nets nor the closing vertical 

 nets worked in deeper zones caught nearly so many of 

 this species as the weighted net ranging down to about 

 ten fathoms. From the frequency with which similar 

 nets and adjacent hauls give widely differing results, we 

 are inclined to regard this as a species which is distributed 

 irregularly in swarms, or patches of greater density. 



MlCROCALANUS. 



The distribution of Microcdlanus jiusillus, G. O. Sars, 

 in our district throughout the year is interesting. It 



