406 BOTANY OF SOCOTRA. 



3. STAURONEIS. 



Stauroneis, Ehr. 1843. 



S. anceps, Ehr. 

 var. amphicephala, Van Heurck Synops. 69, t. 4, ff. 6, 7. 



S. amphicephala, Kiitz. Bacill. 119, t. 3, f. 25. 



Soeotra. Rare. 



Distrib. A widely distributed fresh water species. 



Family 3. GOMPHONEME^. 



GOMPHONEMA. 



Gomphonema, Agh. 1824. 



1. G. intricatum, Kiitz. Bacill. 87, t. 9, f. 4 ; Smith Synops. i. 8, t. 29, f. 

 241 ; Van Heurck Synops. 126, t. 29, several figures ; I am now disposed to 

 think that the differences are too slight to constitute a variety. 



G. intricatum, var., Kitton in Journ. Linn. Soc. xx. 515. 



Soeotra. Not rare. 



Distrib. Common in fresh water, and in many of the European and 

 American sub-peat deposits. 



2. G. affine, Kiitz. Bacill. 86, t. 30, f. 54; Pritchard Infus. 896 ; Raben- 

 horst Stisswasser Diat. 59, t. 2, f. 11 ; Van Heurck Synops. t. 24, ff. 8, 9 ; 

 Kitton in Journ. Linn. Soc. xx. 515. 



Soeotra. Not uncommon. 



Distrib. Island of Trinidad, Norfolk, frequent in fresh water. 



3. G. acuminatum, Ehr. 



var. coronata, Van Heurck Synops. 124, t. 23, f. 15; Kitton in Journ. 

 Linn. Soc. xx. 515. 



G. coronatum, Ehr. ; Kiitz. Bacill. 87, t. 21, f. 12. 



G. acuminatum, var. ft ; Smith Synops. i. 79, t. 27, f. 238 ft. 



Soeotra. Frequent, mixed with the type form. 

 Distrib. Common everywhere. 



