DIATOMACEJE — MR FRED. KITTON. 407 



4. G. Turris, Ehr. Amer. 128 ; Id. Mikrog. many figures ; Klitz. Bacill. 

 87 ; Pritcbard Infus. 889 ; Van Heurck Synops. t. 23, f. 5 ; Kitton in Journ. 

 Linn. Soc. xx. 515. 



Soeotra. Not common. 



Distrib. A widely distributed species. 



5. G. constrictum, Ehr. 



var. subcapitata, Van Heurck Synops. pi. xxiii. fig. 23 ; Kitton Journ. 

 Linn. Soc. xx. p. 515. 



Soeotra. Bare. 



Distrib. I have found this species mixed with the type form in gatherings 

 from America, Java, and West Indies. 



Family 4. ACHNANTHE^E. 

 ACHNANTHES. 



Achnanthes, Bory, 1822. 



A. linearis (Wm. Smith), Grunow, Cleve and Grunow, Beitr. z. Kennt. d. 

 Arctischen Diatom. 23 ; Van Heurck Synops. 131, t. 28, fF. 31, 32 ; Kitton in 

 Journ. Linn. Soc. xx. 515. 



Achnanthidium linear e, Wm. Smith Synops. ii. 31, t. 61, f. 381. 

 A. Jachii, Rabenh. Flor. Europ. Ag. sec. i. 106. 



Soeotra. Frequent. 



Distrib. One of the commonest of fresh water diatoms. 



Family 5. COCCONEIDE^J. 

 COCCONEIS. 



Cocconeis, Ehr. 1835. 



C. pediculus, Ehr. Infus. t. xxi. f. 2 ; Smith Synops. i. 21, t. 3, f. 31 ; Van 

 Heurck Synops. 130, t. 32, ff. 11, 13 ; Kitton in Journ. Linn. Soc. xx. 515. 



Frustulia Lens, De Brebisson. 



Soeotra. Frequent. 

 Distrib. Common everywhere. 



