12 R. Gronblad, New Desmids. 



pi. 38 f. 14—15). var. subabruptum, nova var. Cellulae 

 minores, prae latitudine longiores. Semicellulae apice vix 

 rotundatae subtruncatae; lobo polari plus dilatato medioque 

 incisura minus profunda introrsum rotundata extrorsum an- 

 gulis acutis subaperta dissecto. Membrana in prominentia 

 centrali granulis 3 quasi semicircularibus ornata ceterumque 

 intra margines granulis emarginatis seu verrucis armata. 

 Long. 31,7, lat. 21,8, crass. 14,5, isthm. 6,6 it. [N:o 1009]. 



This variety resembles E. abniptum N d t. on account 

 of its dilated and abruptly truncated polar lobe and the 

 more prominent lateral lobes. Within the polar lobe there 

 are three emarginate granules or verrucae on each side; 

 within the lateral lobes there are two equal granules and 

 also two small simple granules on each side along the 

 margins of the sinus, whereas the margins of the lateral 

 lobes are furnished with 2 — 4 acutely conical granules; the 

 central protuberance possesses 3 rounded granules. 

 Compare also Ducellier, Etude crit. p. 62 fig. 38; E. ab- 

 ruption Nordst., Desm. Brasil. pi. 2 f. 3 and Borge, 

 Regnell exp. pi. 4 f. 23; „E. binale?" Borge, Archang. 

 fig. 37. 



Hab. Raikala near the Imatra Falls (SE), leg. Hj. Hjelt. 

 PI. 3 fig. 27—28. 



Eu. denticulatum (Kirchn.) Gay; R alt's, Brit. Desm. 

 pi. 14 fig. 8 f. (sub. „E. binale var. ,V"); Gay, Monogr. loc. 

 pi. 1 f. 7 (sub. E. amoemim Gay). This species has been 

 crowded with a great number of various forms, which 

 considerably differ from each other. It is a small species 

 with a very delicate structure of the cell-wall, which cannot 

 be clearly seen without a high magnification. The figures 

 published are often very poor, drawn under a low magnifica- 

 tion, the details in outline and especially in the arrange- 

 ment of the granules being quite overlooked. These forms 

 need a complete revision. 1 have figured here a form 

 which resembles E. subrostratum West (Madagasc. pi. 6 

 f. 6), which species perhaps could be united with E. denti- 

 culatum. Long. 28,4, lat. 21,4, isthm. 4,7 .«. [N:o 882]. 



