Naviculacea.] infusoeial animalcules. 483 



Synedka arcHS (Kiitz.) = Eunotia Faha. (Ehr.) — Rather small, 

 with a distinct convex stipes ; wands smooth, laterally linear, sub- 

 attenuate, curved; dorsally linear-lanceolate. Length 1 -300th. 

 Valpraiso and Falkland Islands, on seaweed. 



S. Barlatida. — Tabulate; small; wands exactly linear, truncate; 

 apices with a mucous appendage (barba) ; dorsally elliptic-lanceolate. 

 Length 1 -960th. Marine. 



S. fasciculata. — Small, tabulate, stipes thick, hemispherical ; bacilli 

 linear, subattenuate at the apex, and truncate; dorsally elliptic 

 lanceolate. Length 1 -480 th. 



S. tahilata. — Large, tabulate, stipes short, bacillar, broadly linear, 

 tapering towards the ends ; laterally truncate ; dorsally rounded ob- 

 tusely. Length l-130th to 1-1 20th. 



S. affinis. — llather smaller, tabulate, stipes hemispherical; bacilli 

 hemispherical ; bacilli in pairs, or in fours, often disposed in a cir- 

 cular form, slender, linear, sub-attenuate and truncate at the ends ; 

 dorsally narrowly lanceolate. Length 1 -320th. Adiiatic Sea, 

 Venice, Trieste, Spalato. 



S. Saxonica. — Rather small, slender, linear, laterally truncate at 

 the ends, dorsally narrowly lanceolate ; stipes rather long. Length 

 l-330th. 



S. Ehrenhergii := Echinella capitata (Ehr.) — Largely stalked, 

 bacilli capitate ; attenuate towards each end, which is round and 

 obtuse. 



S. Balmatica. — Large, stipes eventually long and subramose, the 

 branches bearing the wands near theii' extremities ; bacilli linear, 

 rather attenuate towards each end, which is rounded and truncate. 

 Length l-240th. 



S. superla. — Large, turgid, stipes but little elongated ; bacilli rather 

 thick, wadely linear, attenuated towards the ends ; laterally truncate, 

 dorsally narrower, ends rounded and rather obtuse. Length 

 1- 120th to l-84th. Mai-ine. 



S. crystallina. — Very large, stiiated, glistening like silver, when 

 dry ; ciystalline, stipes short and thick ; wands very long, somewhat 

 turgid, linear, ends truncate ; dorsally a\ ith obtusely rounded ends. 

 Length l-60th to l-48th. 



S. gigantea (Kiitz.) — Very long, delicate, and rather tAvisted, 



