The Classification of Lower Organisms 



Fig. 13. — Bacillariacea : a, Mclosira sp., a living cell and an empty one. b, c. 

 Girdle and valve views of cell of Cyclotella sp. d, e. Sections of a valve of Pinnu- 

 laria sp., highly magnified, after Otto Miillcr (1896); d, about half-way between the 

 middle and the end, e^ near the end. f, g, Girdle and valve views of Synedra sp. 

 h, i. Girdle and valve views of Rhoicosphenia curvata. j, k, Girdle and valve views 

 of Navicula sp. 1^ m, Girdle and valve views of Gomphonema sp. (the former show- 

 ing the gelatinous stalk by which the cell is attached), n, o. Girdle and valve views 

 of Cymbella sp. p, q, Surirella saxonica after Karsten (1900); p, two cells joined 

 before conjugation; q, zygote; x 250. r, s, Girdle and valve views of Cocconeis sp. 

 X 1,000 except as noted. 



