104 University of California Publications in Zoology [Vol.22 



numbers distributed over the entire year. The correspondence of these 

 pulses with those of chlorophyll bearers is quite close, thirteen being 

 within seven days of the same date. 



Polyarthra trigla eggs, attached. 



Station I Station II Station III Daily Hourly 



Female, average 35,511 431 40S 723 40,686 



Male average 342 4,100 8,138 



Identification certain. Probably most eggs became detached in 

 manipulations and the records are to that extent unreliable. Certainly 

 there are some very curious features to the records as they stand. 

 Female eggs only were recorded at Station III in the regular series 

 and then in small numbers at wide intervals, but the hourly series 

 from the same canal, but a mile away, showed great numbers of both 

 sexes. At Station II the numbers of female eggs were also scan!: but 

 in the two catches of male eggs one was rather large. At Station I, 

 female eggs appeared irregularly in small numbers from the last of 

 February to the end of March, after which the occurrences were reg- 

 ular and in rather large numbers till May 11 when they abruptly 

 failed. Only a very few catches were found in the interval to mid- 

 November when the occurrence became regular again for several weeks. 

 The records of male eggs came in November. 



Such records are quite unsatisfactory as it is evident that they do 

 not show the real numbers of eggs produced, in view of the large num- 

 bers of females recorded at all periods at all stations. Quite prob- 

 ably many of the free eggs counted as KerateUa and Filinia eggs 

 should have been referred to Polyarthra. This was suspected early 

 in the count and the eggs were frequently examined for distinctive 

 characters in the groups but none were found that could be used accu- 

 rately while counting. 



Rotifer eggs, winter, free, unidentified. 



These were counted merely as a matter of routine in trying to give 

 attention to everything found. There is not enough certainty in any 

 observation concerning them to make comment desirable. 



Synchaeta sp. 



Station I Station II Station III Daily Hourly 



Average 76,696 35,039 83,S65 19,850 25,890 



Identification of genus satisfactory. Judging from living ma- 

 terial, three or more species were represented in the counts but they 



