145 



Inccrtaosedis. • 



Xlil. € > lillflrotlieca Rabenh. (1859.). Frustula exacte 

 fusiformia, utrinque acuta, longitudinaliter costata, costis duabus (rarius 

 1 vel 3) flcxuosis, nodulis nullis. 



C. Gerstenbergeri Rabenh. (Alg. N. 801.). Frustula (in vivis) 

 cylindracea, polos versus obtusiusculos attenuata, in siccis fusiformia, 

 polis acuminatis , costis flexuosis subspiralibus. 



Long. */i 9 — Vis'" = 0,0047—0,0062". 



Hab. in stagnis, fossis per Germaniam passim. 



Rabenhorat, Flora Europaea. 10 



