192 °] Allen: Plankton of the San Joaquin River 61 



Gomphonema acuminatum Ehrbg. Once, III. 



Gomphonema olivaccum Lyngb. Twice, III. 



Gomphonema subelavatum Gniu. 



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. 



Navicula lanceolata Kiitz. Once, II. 



Navicula oblonga Kiitz. 



Navicula pusilla W. Sm. 



Navicula rhomboides Ehrbg. 



Navicula smithii Breb. 



Nitzschia dubia W. Sm. Once, II. 



Nitzschia gracilis Hantzsch. Once, III. 



Pinnularia acrosphaeria Breb. Once, III. 



Pleurostauron obtusum Lagerst. Once, I and II. 



Ehizosolenia longiseta Zach. Once, I and III. 



Rhopalodia gibba O. Mull. Once, I, twice, II. 



Rhopalodia paralella O. Mull. 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 15)15 

 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. 

 Cocconeis pediculus Ehr. 

 Cyclotella meneghiniana Kiitz. 

 Cymatopleura solea (Breb) Grun. 

 Cymatopleura elliptica (Kiitz) W. Sm. 

 Cymbella gastroides Kiitz. 

 Cymbella lanceolata. 

 Cymbella pusilla. 

 Diploneis (Navicula) elliptica. 

 Encyonema turgidum (Greg) Grun. 

 Epithemia gibba (Ehr) Kiitz. 

 Epithemia ocellata Kiitz. 

 Epithemia turgida Ehr. 

 Eunotia robusta. 

 Fragilaria capucina Desm. 

 Gomphonema montanum. 

 Gomphonema constrictum Ehr. 

 Gj'rosigma kiitzingii (Grun) CI. 

 Gyrosigma parkerii. 

 Gyrosigma scalproides (Rabenh) CI. 



