125 



Prapnaldia glomerata, Yauch., Baton Rouge. 



There are a great number of specimens of the Confervoid Algrc 

 and of the UWaoeffl and the genus Closterium undetermined, and 

 manj given in the list are probably only approximations. 



DIATOMACE.l-:. 



ErNOTI.r.. 



Epithemia musculus, K., Lake Pontchartrain. 



Epithemia turgida (?), K., Lake Pontchartrain. 



Epithemia gibba, K., Baton Rouge. 



Epithemia "Westerniannii, K., Baton Rouge. 



Eunotia tetraodon Ehr., Rapides. 



Himantidium pectinale, K., in long filaments and separate valves, 

 Amite river. 



Himantidium bidens, E., Rapides. 



Himantidium, Arcus, E., Rapides. 



Himantidium undulatum, S., Rapides. This species has a gibbous 

 center, three slight dorsal undulations, and obtuse recurved apices, 

 and corresponds with the description of it in Pritchard. The habi- 

 tat indicated in that work is Europe. 



Himantidium parallelum, E. 



FRA GILLARIACELE. 



Fragillaria capucina, Desin., in elongated tapering filaments, Baton 

 Rouge. 



Nitzschia parvula, S., Grand Isle. 

 Nitzschia Dianas, E., Pontchartrain. 

 Nitzschia amphioxys, E., Baton Rouge. 

 Oeratoneis Closterium, E., Rapides. 



surirelle.;:. 



Synedra vitrea, K, Baton Rouge. The valve of this species is 

 beautifully striated, with a quadrangular vacant space in the center. 

 It is linear lanceolate, contracted to slightly dilated, obtuse, rounded 

 ends. The front view is also perfectly transparent; very long; has 

 distinct marginal strirc, and more or less dilated truncate ends. I 



