60 University of California rublicutiuns in Zoology L\''«"22 



failure to decide to reeord it. There is enough record to indicate 

 that it is a warm weather form and not nearly so well represented in 

 the colder months. 



Syncdra ulna Ehrbg. 



Stntion I Station II Station III Daily H.>ur1y 



Average 65.5,7:i0 7.30,.3.S9 744,781 2,351,197 :«).-),160 



Identification uncertain. Probably includes at least three or four 

 other species with possibly some similar genera. Tliis probably ac- 

 counts for the similarity of numbers and distribution at all stations. 

 Maximum in August at Stations II and III, in June at Station I 

 with a large pulse in August. Certainly favored by higher tempera- 

 tures. Losses through net heavy. An important local planktont. 



Tabellaria spp. 



Identification of genus satisfactory. Occurrence at all stations 

 rare. Evidently unimportant here. It was thought that both T. 

 fenestrata and T. flocculosa were recognized a few times. This genus 

 is apparently no more at home here than Kofoid (1908) reported it 

 to be in Illinois. 



The following forms of Bacillariaeeae were recorded only once 



or twice at the three stations, or were thought to be recognized in 



living material: 



Amphora coffeaeformis Ag. Once, I ami twice, 111. 



Amphora sp. Once, I and III. 



Cocconeis placentula Ehrbg. Once, II. 



Cocconeis sp. 



Coscinodiscus sp. Once Stations I and III and daily. 



Cyclotella schroeteri Lemm. Once, I. 



Cymbella helvetica Kiitz. Once, 11 and III. 



Cymbella lanceolata Ehrbg. 



Cymbella parva W. Sm. Twice, I, once at II and III. 



Cymbella pusilla Grun. 



Cymbella prostrata Berk. 



Dentieula sp. 



Diatoma sp. 



Diatoma vulgare Bory. Twice, I, once at III. 



Diatomella sp. Grev. Once, I and II. 



Epithemia granulata Ehrbg. 



Epithemia sorex Kutz. Once, III. 



Epithemia sp. 



Epithemia turgida Ehrbg. Once, II. 



Eunotia flexiiosa Kiitz. Once at Station I, twice at ITT. 



Eunotia major W. Sm. Once, III. 



Eunotia pectinalis Kiitz. 



Fragillaria niutabilis. 



