282 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
vertical hauls, and also the curves for the Diatoms, the 
Dinoflagellates, and the Copepoda in these hauls. The 
way in which the maxima of these three groups follow 
in the usual order is quite evident. On the left hand 
margin of the figure, 4 c.c. represents the volume of the 
total catch at that level; 250,000 Diat: indicates the 
scale upon which the curve for the Diatoms is drawn; 
and 2,000 Copep: shows the relatively larger scale made 
use of for both the Copepoda curve and that of the 
Dinoflagellata. 
DINOFLAGELLATA. 
Turning now from the Diatoms to the other 
Protista, we find that the Dinoflagellata and Noctiluca 
are both worthy of special consideration. The Dino- 
flagellates, although not comparable in importance with 
the Diatoms, are represented in our samples throughout 
the whole year, and in summer are present im 
considerable numbers, as we have shown in the tables 
on pp. 271 and 272. We have printed in the following 
lists all the records of the two types* Peridiniwm 
divergens and Ceratium tripos, both in bay and sea (the 
average of all the comparable nets used on each 
occasion). The results for the sea are enclosed in square 
brackets. 
Ceratium Peridinium Ceratium Peridinium 
Date. Bay and_ Bay and | Date. Bay and Bay and 
[Sea]. [Sea]. [Sea]. [Sea]. 
January 3 340 0 February 19 400 0 
6 175 0 22 300 0 
13 650 0 25 150 0 
18 300 0 28 100 0 
21 200 0 March 3 25 0 
24 150 0 7 550 0 
29 50 0 11 100 0 
February 1 1,240 0 15 450 0 
5 145 0 19 600 0 
8 250 0 22 0 0 
12 450 0 26 1,050 0 
17 150 0 29 550 0 
* Hach of these may possibly include a few allied species or 
varieties or ‘‘forms’’; under Ceratiwm, for example, we put any 
members of the C. tripos group. 
