84 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
The two species of Cladocera found in our district, 
Podon intermedium and Hvadne nordmanni, occur mainly 
in summer, in a wide sense, ranging from the end of 
March to the beginning of October. Our first record of 
Podon is six specimens on March 26th, and the last is fifty 
on October Sth. Evadne begins with ten on March 29th, 
reached 500 on April 9th, and ends with 50 on September 
20th. Tens, twenties and thirties are common numbers in 
the records of both species, but sometimes the hundreds 
are reached. Asa rule there is no great difference between 
surface and deeper hauls, and occasionally there is a 
great constancy of results, indicating an _ even 
distribution :-—e.g., on April 18th at ten miles out. 
0, 
At Station II. Surface nets. 10faths. Shear. 
Podon intermedium 4 Wei Te) — fie? 
Evadne nordmanni ie 100 100 150) -S@erG 
On April 19th, in the bay, two similar surface hauls 
took 40 and 87 Podon, and 75 EHvadne each; and at the 
same time, at Station II, ten miles off, the two surtace 
nets took 40 Podon and 75 Evadne each. Other similar 
cases might be quoted; but on the other hand there are 
diverse hauls on other dates showing a very uneven 
distribution. The numbers during May and June are 
relatively high :— 
Podons, 22. 190 80 150 100 100 150 
Hivadne ... 60 80 300 300 300 650 
This is the highest point reached by Hvadne, and this 
form is practically absent, or only occasionally present, 
during the latter half of August and parts of September. 
Podon reaches a climax (500) rather later, on August 
13th, and soon after that drops to tens and even units, with 
an occasional appearance (August 31st, 200) in greater 
numbers. During most of September the groupis but 
