PLATE LXXXVIII. 



FIGS. PAGE 



1-3. Cosmarium formosulum Hoff. 1, x 570 (after 



Nordstedt); 2, x 520; 3, x 400 . . 240 



45. C. formosulum var. Nathorstii (Boldt) West & 

 G. S. West. 4, x 550 (after Boldt) ; 5, x 

 550 . . . . .242 



Fig. 46 is a copy of Boldt's figure of the ver- 

 tical view,, but we think it slightly incorrect. 

 The granules in the centre should not be so 

 strongly marked. In the specimens we have 

 examined they were scarcely discernible. The 

 granules are likewise not shown on the median 

 inflations. 



6. C. subreniforme Nordst. x 570 (after Nordstedt) 243 



7. C. pycnochondrum Nordat. x 570 (after 



Nordstedt) . . . .244 



8. C. didymoprotupsum West & Gr. S. West. x 



500 . . . . .192 



9. C. pulcherrimum Nordst. x 570 (after 



Nordstedt) . . . .245 



10-14. C. binum Nordst. 10 and 11, x 520; 12, x 

 about 640 (after Raciborski) : 13 and 14, 

 smaller forms, x 520 . . . 246 



Fig. 12 is a copy of C. binum " var." Racib. 

 (1889). It will be observed in the specimens 

 figured that the number of marginal crena- 

 tions is variable, the fewest number being 

 exhibited by fig. 14. 



