294 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
The minor maxima of Pseudocalanus and Oithona in 
March and April and of O7thona and Temora in June will 
be noticed; but the much greater maxima of all species 
about the middle of September and again in the 
second week of October is the most conspicuous feature 
of the list. On the whole, Copepoda were most abundant 
within the bay this year in the third week of September 
(over 64,000 in one haul on September 14th, and over 
45,000 on September 16th). The distribution of some of 
the more important Copepoda throughout the year will be 
considered further on. 
[IN \ THE, OPEN W@SHAGa 
The plankton samples from the open sea to the south 
and west of the Isle of Man were taken from the 
S.Y. “Ladybird” during the two critical periods of the 
year (April) and late summer (August and September), 
when certain constituents in the plankton attain their 
maxima of development; and these may now be considered 
in relation to the other observations discussed above which 
were taken throughout the year from smaller boats in the 
inshore waters of Port Erin Bay. 
During the spring, part of a month (April 11th to 
April 29th) was devoted to this work at sea from the 
‘ Ladybird,” and in the 15 working days during that 
period we took in all 184 samples, an average of over 14 
per day. For example, on April 29th, 20 hauls were 
taken at Stats. I, IJ and III with Hensen, Nansen, surface 
(fine and coarse), weighted and shear nets—a collection 
which enables comparison to be made between these 
localities with the different nets and within a few hours of 
the same time. 
In the summer and autumn (August 4th to 
September 19th) the ‘ Ladybird” was again engaged on 
