244 DE. JULIUS SCHAAESCHMIDT ON AFGHANISTAN ALCLffl. 



form from the rounded cells (fig. 9) by repeated division of these 

 cells. 



6. Nostoc sp. ? Size : family 0*135 millim. ; cells 0003 millim., 

 by one third as loiig. 



7. Gtlceotrichia sp. ? Insufficient material. Size : cells at 

 the base of the filament 0-007-0*008 millim. by one half as 

 long; resting spore 0015 millim. X 0*012 millim. ; heterocyst 0*008 

 millim. 



BACILLABIACEiE. 



8. Eucyonema venteicosum (Kutzing), Grunow; Van 

 Heurck, 'Synopsis des Diatomees de Belgium] t. iii. f. 15. Size 

 0*058 x 0*014 millim. 



Also "forma interim cmpitosum et Lunula" Yan Heurck, I. c. 

 t. iii. f. 18. Size 0033-0-046 millim. x 0*010-0014 millim. In 

 conjugation also. 



9. Stauboneis Phcsnicenteeon, Ehrenberg ; Van Heurck, I. c. 

 t. iv. f. 2. Size 0*070-0*078 millim. x 0*015-0020 millim. 



10. S. acuta, W. Smith, nov. f. tenuis ; lateribus lsevissime 

 concavis, area lineari, non dilatata. (Plate V. fig. 11.) Long. 

 0*100 millim., lat. max. 0*014 millim. 



11. S. dilatata, W. Smith, British Diatomacece, p. 60, t. xix. 

 f. 191. Size 0046 x 0016 millim. 



12. S. anceps, Ehrenberg, nov. f. intermedia. Between the figs. 

 4 and 5 of Van Heurck, I. c. t. iv. ; bridge parallel. Size 0060 x 

 0012 millim. 



nov. f. tenuicollis ; sub polis valde constricta. (Plate V. 



fig. 12.) Long. 0*040 millim., lat. max. 0*012 millim. 



13. Navicula vieidis, Kutzing, var. commutata, Grunow, 

 Van Heurck, I. c. t. v. f . 6. 



nov. f. longior. Size 0*060 x 0*010 millim. 



14. N. Bkebissokii, Kutzing; Van Heurck, I.e. t. vi. Size 

 0*060-0098 millim. x 0*010-0015 millim. 



15. N. Tabellaeia {Ehrenberg, p. p.), Grunow. Size 0070- 

 0*078 millim. x 0011-0*020 millim. 



16. N. appendiculata, Kutzing ; Van Heurck, I. c. t. vi. f . 18. 

 Size 0*038 x 0*008 millim. 



