60 ERNST 0STRIP 



Fragilaria producta Lgst. Lgst. Spb. If), Tab. I, fig. 1 (F. aequalis 

 prod.). 



41 samples (S. (5, S.W. 12, N.W. 2, X. 8, F. U . 

 Area: B. E., Spb. 



Fragilaria rhombica sp. nov., Tab. nost. V, lig. 80. 



Long: !(')//, Int: In, sir. 10 in 10 n. 



Valva rhomboidea, apices subcapitatos versus valde altenuata. 

 Striis medium partcm valvne versus obliteranlibus ibi(|ue areolam 

 centralem relinqventibus. 



Grimscy (X.) O. I). 



I think this small Fragilaria is probably to be considered as an 

 intermediate form between F. constr. venter and F. Ilarrisoni. 



Fragilaria Smithiana Grun. V. H. Syn., Tab. XLV, lig. 1. 

 Ulfjulsvaln S.) A. F. 

 Area: Eur. 



Fragilaria triundulata sp. nov., Tab. nost. V, fig. 81. 

 Long: 2C. 11, lat: 6,7 /<, sir. !(>,(> in 10 //. 



Valva leniter triundulala, apicibus capitalis. Striis marginalibus, 

 aream aj)icalem lalain relinquentibus. 



Apavatn S.) B. P. 



This form has nothing to do with Fr. construens var. triundulata 

 Reicbelt (en IV. Osl. Dint. Ail. 57, Tab. II, lig. 15). Possibly it is more 

 closely related to Frag, trigibba Pant. (Pant. Hal. S. 79, Tab. IX, fig. 224 , 

 but it is scarcely identical with it. 



Fragilaria undata W. Sin. V. H. Trt. 324. A. S. All., Tab. CCXC, 

 ligs. 48-(H. 



5 samples (S.W. 2. X. 1, E. 2). 



Area: Fur., Grl. 



In tab. nostr.. lig. S2, I have given a figure of a particularly elegantly 

 built form of Frag, undata. It was found in a sample from West Ice- 

 land. SI 



*Fragilaria virescens Kalis. V. H. Trt. 323, Tab. XI, lig. 442. 

 ::() samples S. 5, S.W. 15, X.W.I, X. 5, E. 15, s. 1. 1). 

 Area: Fur., At'., As., Am., Grl. 



Var.? (>.ri !f ua Grim. V. H. Syn., Tab. XLIV, ligs. 2 3. 

 (i samples S. 2. X. 2, K.I, s. 1. 1). Hot spring: 1. 

 Area: Fur. 



Meridion Agardb 1847. V. H. Trt. 347. 



:i: Meridion circulare Ag. V. H. Trl. 347, Tab. XI, (ig. 474. 



15 17 samples (S. 111). S.W. 71, X.W. 15, X. 40. F. 157, s. 1. 4). Hot 

 springs: 12. 



Area: Fur., A I'., As., Am., Grl. 



