1920] Allen: Plankton of the San Joaquin River 61 



Gomphonema acuminatum Ehrbg. Once, III. 



Gomjihonema olivaceum Lyugb. Twice, III. 



Gomphonema subclavatum Grun. 



Gyrosigma attenuatum Kiitz. Once, III. 



Mastogloia braunii Grun. Twice, II and III. 



Mastogloia sp. Once, II. 



Melosira subflexilis Kiitz. Once, II. 



Navicula helvetica J. Brun. Once, III. 



Navioula lanceolata Kiitz. Once, II. 



Navicula oblonga Kiitz. 



Navicula pusilla W. Sm. 



Navicula rhomboliles Ehrbg. 



Navicula smithii Breb. 



Nitzschia dubia W. Sm. Once, II. 



Nitzschia gracilis Hantzseh. Once, III. 



Pinnularia acrosphaeria Breb. Once, III. 



Pleurostauron obtusum Lagerst. Once, I and II. 



Ehizosolenia longiseta Zach. Once, I and III. 



Ehopaloflia gibba 0. Miill. Once, I, twice, II. 



Rhopalodia paralella O. Miill. Once, II. 



Stephanodiscus sp. Twice, I, once, II. 



Surirella spiralis Kiitz. Once, II. 



The following list of forms, identified by Professor C. J. Elmore 

 of Grand Island College in Nebraska from material collected in IDlf) 

 and sent to him for naming, will prove of interest for comparison. 



Achnanthes lanceolata (Breb) Grun. 

 Amphora ovalis. 

 Asterionella gracillima Heib. 

 Amphiprora ornata Bailey. 

 Bacillaria paradoxa Gmel. 

 Ceratoneis arcus Ehr. 

 Coccoueis pediculus Ehr. 

 Cyelotella meneghiniana Kiitz. 

 Cymatopleiira solea (Breb) Grun. 

 Cymatopleura elliptiea (Kiitz) W. Sm. 

 Cymbella gastroides Kiitz. 

 Cymbella lanceolata. 

 Cymbella pusilla. 

 Diploneis (Navicula) elliptiea. 

 Encyonema turgidum (Greg) Grun. 

 Epithemia gibba (Ehr) Kiitz. 

 Epithemia ocellata Kiitz. 

 Epithemia turgida Ehr. 

 Eunotia robusta. 

 Fragilaria capucina Desm. 

 Gomphonema montanum. 

 Gomphonema constrietum Ehr. 

 Gyrosigma kiitzingii (Grun) 01. 

 Gyrosigma parkerii. 

 Gyrosigma scalproides (Eabenh) CI. 



