"pvuring the time 1 have been occupied with the Desmids, 

 *~J a considerable amount of forms which could not be 

 identified with any known Desmid was met with. Most of 

 them (excepting the Staurastra, which will be published 

 later on), are brought together in this paper. Moreover, 

 there will be critical rewiews of some species already known. 

 The samples are collected in many parts of Finland *) 

 but also from adjacent parts of Northern Russia. My own 

 collections were made at the following localities; Keuru (C); 

 around Tammerfors in Messuby, Birkkala, Lempaala, Teisko 

 (W); Domargard near Borga (S); Helsingfors (S); Bjorko in 

 Esbo skargard (S); Jusaro in Ekenas skargard (S); around 

 Viborg, Nyslott, Sordavala and Kexholm (SE). 2 ) Further- 

 more a very interesting collection of samples was given to 

 me for examination by Prof. F. Elfving including some from 

 Abo, Nadendal, &c (SW), and Helsingfors (S) collected by 

 himself about 1875; further one from Raikala near the 

 Imatra Falls (SE) and two from Karkku (W) collected by 

 Hj. Hjelt; one from Ispois (SW) collected by 0. M. Reuter 

 at the same time; one from Kimito (SW) collected by 

 H. Waren. Many samples from Esbo (S) and some from 

 Aland (SW) were collected by Mr C. Cedercreutz; some 

 from Enontekis Lappmark (NW) by Mr M. Kotilainen; plankton 

 from Vuoksen by Prof. K. M. Levander. In 1918 I have 



M For the various parts of Finland are the following abbreviations 

 used: (N) = Northern, (S) = Southern, (E> = Eastern, ( W) = Western, 

 (C) = Central- Finland. 



2 ) Collected during an excursion made in SW-Finland 1919. To 

 the „Societas pro Fauna et Flora Fennica" I am indebted for a pecuniary 

 grant for this purpose. 



