194 KAARE MÜNSTER STRØM. 



Explanation of Plates. 



All the figures are drawn to scale by means of the greatest „Zeichen- 

 apparat nach Abbe" from Zeiss. The microscope used was the greatest of 

 Zeiss, vis. I b., with the objectives as, aa, B, DD, 3 mm, 2 mm, and also the 

 objectives of Reichert, 3, 7a, 3 mm. — The eye-pieces used were 2, 4, and 

 the compensating 2, 6, 12, 18, from Zeiss. 



Plate m. 



Fig. 1. Gymnosyga monoUformis. Ehrbg. (790 x.) 



Figs. 2, 3 & 4. Euastrum Tuddalense. sp. nov. 2 front view, 3 side view. 

 4 vertical view. All the three figures were drawn from diffe- 

 rent specimens. (2. 1250 x, 3 & 4. 1180 x.) 

 Fig. 5, Micrasferias conferta. Lund, forma, in West. Brit. Desmid. 



(790 X.) 

 Fig. 6. Euastrum hinale. (Turp.) Ehrbg. forma. (1175 x.) 

 Figs. 7 & 8. Cosmarium pseudarctoides. (Turn.) nob. (1520 x.) 

 Figs. 9, 10, 11 & 12. Characiopsis crassi-apex. Printz. (790 x.) 

 Fig. 13. Staurastrum controversum. Breb. forma. Vertical view. (790 x.) 

 Fig. 14. Arthrodesmus sp. (790 x.) 



Fig. 15 Sphcerososma granulatum. Roy & Bissett. (790 x.) 

 Figs. 16, 17, 18 & 19. Heterocope saliens. (Lilljeb.) G. 0. S. 15. urosorae, 

 16 & 18. fifth leg, 17. first antenna. (15 & 17. 62 x, 16. 380 x, 

 18. 96 X.) 



P 1 a t e IV. 

 Fig. 1. Cosm^arium quadrifarium. Lund. Central granules. (1075 x.) 

 Fig. 2. Tetmemorus BrebissonU. (Menegh.) Ralfs, var. minor. De Bary. 



(790 X.) 

 Fig. 3. Cosmarium contractum. Kirchn. var. elUpsioidewn. (Elfv.) 



W. & G. S. West, forma 1. in West. Brit. Desmid. (790 x.) 

 Fig. 4. Peniuin Cucurbitinum. Bissett. (1180 x.) 

 Figs. 5 & 6. Cosmarium, Quadrum,. Lund, forma. 5. front view, 6 vertical 



view. (The granules are not drawn.) (5. 760 x., 6. 380 x.) 

 Fig. 7. Cosmarium taxichondrum. Lund, forma. (Two cells just after 



division.) (790 x.) 



