134 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
Diatoms, Dinoflagellates and Copepoda—were higher in 
June. Apparently the greater bulk of the catches on some 
occasions in May was due to the unicellular Alga Halosphaera. 
The autumnal maximum was very slightly marked this 
year. In 1913, we recorded an unusually low autumnal increase, 
with an average of 8-4 c.c. in September, and a maximum 
of 15:2 c.c. This year the numbers are only slightly higher, 
the average for October bemg 8°9 c.c., and the maximum 
catch being 19 ¢.c. (on September 30th). 
There seem to have been no vast swarms of Diatoms 
this year in our district, such as we have had to record in 
some previous years. The maximum haul was about 19 
millions on June 15th, whereas we recorded hauls of from 
150 to about 200 millions in the three previous years. 
Our detailed analysis of the more important genera of 
Diatoms does not show anything of outstanding importance, 
but, for the most part, simply confirms what we have stated 
in previous reports. It may be remarked, however, that 
Coscinodiscus was unusually abundant in the spring of 1915. 
The maximum for this genus was in April, and a record haul 
of nearly 5 millions was obtained on April 13th. 
The Dinoflagellata (Ceratiwum and Peridinium) _ were 
more abundant in 1915 than usual. The maximum for both 
genera was in June, a month later than in 1914. The largest 
hauls were 264,000 of Ceratiwm tripos on June 21st, and 110,000 
of Perrdinvum spp. on June 3rd. 
The maximum of adult Copepoda was this year in August 
(117,340 on August 2nd), but the highest monthly average 
was in October; while that of the Copepod nauplii was in 
June. Our analysis of the eight commonest species of Copepoda 
shows nothing exceptionally noteworthy in their occurrence 
durmg 1915. In some cases the autumnal numbers were 
relatively higher than usual. 
The remaining groups of animals (such as Medusae, 
