SEA-FISHERIES LABORATORY. 133 
AN INTENSIVE STUDY OF THE MARINE 
PLANKTON AROUND THE SOUTH END OF 
THE ISLE OF MAN.—PART IX. 
By W. A. Herpman, F.R.S., ANDREW Scott, A.LS., 
and H. Maset Lewis, B.A. 
[ABSTRACT ONLY. ] 
In this ninth year of the intensive study of the plankton 
in the central area of the Irish Sea, although our operations 
have been greatly restricted by war conditions, we have 
managed to get 320 samples for examination, spread fairly 
equally over the twelve months, in numbers varying from 
21 to 27 a month. By getting a special permit from the 
authorities, we have been enabled to take these gatherings 
‘in the usual way across the mouth of, and just outside, Port 
Erin Bay. These bring our total number of samples for the 
nine years up to 4,620, a very substantial number. We still 
hope to complete our ten years of work, and then to publish 
a final report upon the observations of the decade. 
We have prepared, in manuscript, a complete report 
on the year’s observations on the usual lines, with tables of 
statistics, and curves, in the hope that we may be enabled 
to publish these data with the final report next year. In the 
meantime we content ourselves, for the reasons which are 
stated in the Introduction (p. 99), with the following brief 
account of the results obtained in 1915. 
The spring maximum this year was again in May, as it 
was in 1911, 1913 and 1914, the average haul of the total 
catch for that month being 63°5 c.c., the highest monthly 
average in any year we have yet recorded. The actual largest 
haul was 116°5 c.c., on May 10th. But, although the highest 
monthly average of the total catch was in May, the monthly 
averages of the three most important groups in the plankton— 
