32 I'niri rsifii of California Publications in Zoology [Vol. 

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



Number Hourly 



of . ■ 



forms Total Average 



Total Phvtoplanktonts 61 476,644,270 32,172,8 



Bacteriaceae 1 112,192 8,6 



Schizophyceae 12 64,886,064 499,1 



Chlorophyceae 10 22,150,470 1,703,S 



Bacillariaceae 32 377.380,220 29,029.2 



Conjugatae 6 12,115,324 931,8 



Total Zooplanktonts 72 179,588,061 13,814,4 



Mastigophora 15 51,114,592 3,931,8 



Rhizopoda 8 5,160,360 396,9 



Heliozoa 4 5,739,216 441,4 



Ciliata 6 40,775,578 3,136,5 



Suctoria 1 25,600 1,9 



Total Protozoa 34 102.S15.346 7,908,8 



Rhizota . ... 3 209,888 16,1 



Bdelloida 2 2,930,384 225,4 



Ploima 29 70,717,663 5,439,8 



Total Rotifera 34 73,857,835 5,681,3 



Cladocera 2 451,776 34,7 



Copepoda 2 2,463,104 189,4 



Total Entomostraca 4 2,914,880 224,2 



Miscellaneous 



Total Planktonts enumerated 133 656,232,331 45,987,2 



Synthetic 527,758,862 36.10t,7 



Analytic 128,473,469 9,882,5 



COMPARISON WITH ILLINOIS FORMS 



As in the case of the 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 

 Bacteriaceae 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 II and 1.5 

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

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



