Acta Societatis pro Fauna et Flora Fennica, 49, N.o 7. 



35 



Forma granulis intra margines laterales 4 utrimque ornata. 

 Long. 28, lat. 25, isthm. 8 /<, [N:o 905]. 



Very much resembles the form of E i c h 1 e r (Flor. 

 Miedz. pi. 3 f. 14), but differs from this by the entirely 

 smooth (not undulate) margins. 



Hab. Keuru (C). - PI. 7 fig. 4—6. 



C. sphagnicolum West, Mngr. Ill pi. 71 f. 11 — 14 var. 

 incisum, nova var. Cellulae minores; a fronte visae medio 

 incisura introrsum acuta lineari, extrorsum extremo dilatata 

 profunde constrictae. Anguli infimi rotundati, supremi ob- 

 tusi, laterales granulis singulis instructi; praeterea membrana 

 sub angulos supremos granulis singulis ornata, ceterum 

 glabra. A vertice visum extense sexangulare medio non 

 tumidum. Long. 7,9, lat. 7,9, isthm. 2,6, crass. 3,5 /<. [N:o 1024]. 



Hab. Hirvensalo (SW), leg. Elfv. PI. 7 fig. 27—27'. 



C. polygonum (Nag.) Arch. var. hexagonum nova var. 

 Cellulae dimidio fere minores medio sinu anguste lineari 

 extrorsum dilatato profunde constrictae. Semicellulae sex- 

 angulares lateribus non retusis, in centro prominentia magna 

 obtusata; membrana in angulis apicalibus et lateralibus intra 

 margines granulis singulis minutissimis ornata. A vertice 

 visum ut forma typica. Long. 9,2 — 9,9, lat. 9,2, isthm. 2,5, 

 crass. 6,6 t u. [N:o 1121]. 



Compare also C. bireme Nordst.; West, Mngr. Ill pi. 

 71 f. 36 — 37 which in other respects better agrees with 

 our variety, but possesses a different central papilla. 



Hab. Gov. of Archangel. — PI. 7 fig. 24—26. 



C. pseudoretusiforme, nova sp. Cellulae minutissimae 

 medio sinu anguste aperto acuto profunde constrictae. Semi- 

 cellulae trapeziformes angulis basalibus rotundatis, apicalibus 

 subrotundatis; lateribus retusis parte basali prominenti; apice 

 rectissimo. A vertice visum subrectangulare polis rotundatis; 

 lateribus medio utrimque subtumidis. Membrana plane glabra 

 (aut intra angulos granulis minimis difficillime quidem conspi- 

 cuis ornata?). Long. 7,3—7,9, lat. 8—7,2, isthm. 2fi. [N:o 1025]. 

 Compare C. subretusiforme West, Mngr. II pi. 62 f. 19 

 which differs with a much broader isthmus and quite a 



