32 



University of California f^ubtications in Zoology [Vol.22 



Text Table 1. — Total Planktonts by Major Groups — Concluded 



Number Hourly 



or ■ . 



forms Total Average 



Total Phvtoplanktonts 61 476,644,270 32,172,832 



Hacteriaceae 1 112,192 8,630 



Wohizophvceae 12 64,886,064 499,123 



Chlomiiirvcoae 10 22,150,470 1,703,883 



Bacilhuiaceac 32 377,380,220 29,029,248 



ConjuKatao 6 12,115,324 931,948 



Total Zooplanktonts 72 179,588,061 13,814,465 



Mastigophora 15 51,114,592 3,931,892 



Rhizopoda 8 5,160,360 396,950 



Heliozoa 4 5,739,216 441,478 



Ciliata 6 40,775,.578 3,136,583 



Suctoria 1 25,600 1,969 



Total Protozoa 34 102,815.346 7,908,872 



Rhizota 3 209,888 16,145 



Bdelloida 2 2.930,384 225,414 



Ploima 29 70,717. .563 5,439,813 



Total Rotifera 34 7.;,s.".7>:;,-, 5,681,372 



Cladocera 2 l.'.l,77Ci 34,752 



Copepoda 2 2,463,104 189,469 



Total Entomostraca 4 2,914,880 224,221 



MiscpUaneous 



Total Planktonts enumerated 133 656,232,331 45,987,297 



Synthetic 527,758,862 36,104,724 



Analytic 128,473,469 9,882,573 



COMPARISON WITH ILLINOIS FORMS 



As in the ease of tlie Illinois River, this table shows plants to be 

 more numerous than animals, though they are generally smaller. The 

 disparity in numbers is slightly different being, in recorded order of 

 stations 2.5, 9, and 9 to 1, instead of 5 to 1 as in the Illinois River. 

 The preponderance of Rotifera and Protozoa over Entomostraca is 

 less marked than in Illinois, being 8.5, 45, and 50 to 1 ; and 9, 180, 

 and 151 to 1, respectively. The numbers of Rotifera and Protozoa 

 are not markedly different from each other in Stockton Channel 

 though Protozoa are four or five times as numerous as Rotifera at 

 the other two stations. In Stockton Channel synthetic organisms are 

 relatively few even among plants proper. In this place the principal 

 food of the zooplankton, therefore, is probably furnished by the 

 Baeteriaceae and other saprophytic plants. For this reason the 

 forms of plankton usually rated as important in more or less direct 

 support of a fish fauna are few in kinds if not in numbers, although 

 there is a conspicuous animal population. 



At Station I, Copepoda (including immature forms) outnumber 

 Cladocera about 18 to 1, but only about 2 to 1 at Station 11 and 1.5 

 to 1 at Station III. Protozoa are 1210, 500, and 404 to 1 of the 

 Cladocera, distributed as follows: Rliizopods 45, 22, and 32 to 1, 



