214 



THALLOPHYTA. 



[CH. 



Fig. 41. A. Cells of Gycadeoidea gigantea Sew. x 355. B and C. Parenchy- 

 matous cells and scalariform traoheids of Osmundites Dowkeri Carr. x 230. 



D. Epidermal cells of Memecylon {MelastoTnaceae) with vacuolated contents. 



E. Peronosporites antiquarius Smith, (No. 1923 in the Williamson collection). 

 X 230. F. Zygosporites. x 230. (A, B, C and E drawn from specimens 

 in the British Museum ; D from a drawing by Prof. Marshall Ward ; F from 

 a, specimen in the Botanical Laboratory Collection, Cambridge.) 



