38 R. Gronblod, New Desmids. 



delicate and difficult to discern: there is one central pyrenoid 

 in each semicell and four to six radiating plates. 



Hab. A basin in the Botan. Garden Helsingfors (S). — 

 PI. 7 fig. 39—41. 



C. subtile (West) Liitkem., Desm. Bohm. p. 494. 

 var. subsparsepunctatum, nova var. Cellulae ad apices 

 versus non aut vix attenuatae, apicibus semper rotundatis, 

 lateribus medio levissime late subconstrictis. Membrana 

 sparse ordinibus transversalibus 2- 3 pororum ornata, ad 

 isthmum quidem glabra. Massa chlorophyllacea in utraque 

 semicellula nucleis amylaceis singulis (interdum unus tantum 

 in ipso isthmo situs) lamellisque radiatim exeuntibus (saepe 

 6) composita. Long. 14,5 — 15,8, lat. max. 10,5/*. [N:o 1184]. 



Compare also C. subtile f. West, Frw. alg. Columbia 

 p. 1041 pi. 22 f. 51; and Dysphinctium sparsepunctatum 

 Schmidle, Alpin. Alg. p. 348 pi. 15 f. 1—7. Some forms 

 of the latter are in front view nearly identical with our 

 variety, but, according to the author, the vertical view is 

 elliptical. 



Hab. Bjorko in Esbo (S). - PI. 7 fig. 34-37. 



C. gostyniense (Racib.) nob. (Synon. = C. abruptum 

 Lund. var. gostyniense Rac, Desm. Polon. pi. 11 f. 13). 

 Cellulae parvae medio incisura anguste lineari profunde 

 constrictae. Semicellulae subtrapeziformes angulis basalibus 

 subrectis, lateribus divergentibus levissime retusis, apice 

 levissime retuso, angulis superioribus oblique truncatis et 

 retusis. A vertice visum oblongum medio utrimque pro- 

 minentia papilliformi instructum. Membrana subtiliter porosa. 

 Long. 17, lat. 14,5, crass. 9, isthm. 4,6/*. [N:o 1020]. 



The Finnish form agrees quite well with Raciborski's 

 description but possesses a somehwat broader apex, more 

 abruptly truncate upper angles and a colourless cell-wall. 



Hab. Near Abo (SW), leg. Elfv. — PI. 7 fig. 32-33. 



C. angulosum Breb. var. scrobiculatum, nova var. 

 Semicellulae apice angustiore, angulis superioribus valde et 

 abrupte truncatis, lateribus brevioribus, angulis basalibus 

 non rotundatis subrectis; membrana in centro semicellu- 



