DIATOMACE^E— MR FRED. KITTON. 405 



2. N. elliptica, Kiitz. Bacill. 98, t. 30, f. 55. 



N. ovalis, Smith Synops. i. 48, t. 17, f. 55 ; Pritchard Infus. 1861, 399 ; Schmidt Atlas d. 

 Diatom, t. 7, ff. 27-32 ; Van Heurck Synops. 92, t. 10, f. 10 ; Kitton in Journ. Linn. Soc. 

 xx. 515. 



Soeotra. Rare. 



Distrib. A widely distributed fresh and brackish water species. 



3. N. mutica, Kiitz., var. Cohnii, Hilse. 



Stauroneis Cohnii, Hilse in Ber. d. Schlesisch-Gesellsch. 1860; Van Heurck Synops. t. 10, f. 17. 



Soeotra. Very rare. Detected by Dr Bossey. 



Distrib. I have found this species in washings of Sphagnum, and in the 

 green slime produced by the leakage of cisterns, &c. Europe, North and South 

 America, India. 



2. MASTOGLOIA. 



Mastorjloia, Thwaites, 1848. 



1 . M. Dansei, Thwaites ; Smith Synops. ii. 44, t. 62, f. 388 ; Pritchard 

 Infus. 924, t. 15, f. 30 ; Van Heurck Synops 92, t. 10, f. 12 ; Kitton in Journ. 

 Linn. Soc. xx. 515. 



Dickieia Dansei, Thwaites in Ann. Mag. Nat. Hist. sec. 2, i. t. 22, f. k. 



Soeotra. 



Distrib. A common brackish and fresh water species. 



2. M. lanceolata, Thwaites ; Smith Synops. ii. 64, t. 54, f. 340 ; 

 Pritchard Infus. 924 ; Van Heurck Synops. 70, t. 4, ff. 15, 16, 17. 



Navicula Meleagris, Kiitz. Bacill. 92, t. 30, f. 37 ? 



Soeotra. Not frequent. 



Distrib. A common brackish water species, less frequent in fresh water. 



3. M. elliptica, Agh. 



M. elliptica {Dansei var. ?) Van Heurck Synops. pi. iv. f. 19 ; Journ. Linn. Soc. xx. 515. 

 Frustulia elliptica, Agardh. 

 Amphora ? elliptica, Kiitz. 



Soeotra. Rare. 



Distrib. Baltic, Trieste, Breydon, and Flordon (Norfolk). In the last 

 named habitat the water is perfectly fresh, the other localities are salt and 

 brackish water. 



