PLATE CXVIIL 



FIGS. PAGE 



i 3. Xanthidium Eobinsonianum Arch. x 500. 

 These drawings are from specimens distri- 

 buted in Wittr. & Nordst. Alg. Exsic. no. 550, 

 and were collected in Derrytrasna Hog, 

 Armagh, Ireland . . .83 



4-6. Staurastrum Meriani Reinsch. 4, x 400; 5 



and 6, x 500 . . . . 122 



TSt. Capi'tulum Breb. x 520 . .124 



8. St. Capitulum var. apitsbergense (Nordst.) 



Cooke. x 400 (after Nordstedt) . .126 



9. St. Capitulum var. tumidiusculum (Nordst.) 



W. & GL S. West. x 400 (after Nordstedt) 126 

 St. Capitulum Breb. x 460 . .124 



St. pileolatum Breb. 11, x 500; 12 and 13, 



x 520 ... 127 



14. St. pileolatum var. cristatuin Liitkem. x 500 129 

 15. St. rhabdophorum Nordst. x 570 (after Nord- 

 stedt) . . '. .129 

 16-20. St. miiticum Breb. 16-19, x 520; 20, zygo- 



spore, x 400 (after Ralfs) . .133 



