PI. cell. aph. 1. HYDROPHYTE. 14% Diatoma. 295 
XIV. 14. DIATOMA. De Candolle. Diatome. 
Threads jointed, flat, simple, coupled throughout their 
whole length ; joints separating, but remaining adherent 
by their alternate angles, with a longitudinal band formed 
by the coupling together of the threads. 
1 . Diatoma Swartzii . Swartz's diatome. 
Fresh water ; threads light-green ; joints half as long as 
broad, crenately notched on both edges, when uncoupled 
triangular. 
Diatoma Swartzii, Agardh Syn. 118. 
Ditches and stagnant waters, among confervae. 
Threads very brittle, slimy, when coupled separating 
suddenly into joints on the least touch. 
2. Diatoma flocculosum. Flocculent diatome. 
Fresh-water; threads hyaline, forming brownish tufts ; 
joints rather broader than long, transversely streaked ; band 
longitudinal, pellucid. 
Conferva flocculosa, Roth Cat. 1, 192 ; Engl. Hot. 1761. 
Diatoma llocculosa, Agardh Disp. ed. 1,35. 
Tift small; threads very minute; joints 4-cornered, edge 
even. 
3. Diatoma tenue. Slender diatome. 
Fresh-water ; threads very small, reddish and brownish; 
joints 3 times as long as broad, transversely streaked ; band 
longitudinal, pellucid. 
Conferva flocculosa. Ft. Ban. 1487. 
Diatoma tenuis, Agardh Decad, 10. 
Diatoma flocculosa /3, Agardh Syn. 120. 
In ditches, on confervse. 
Threads very minute, stiff, hyaline. 
4. Diatoma marinum. Sea diatome. 
Marine; threads simple, in tufts, yellowish ; joints half 
as long again as broad, with ovate, transverse granules. 
Diatoma flocculosum ? Be Candolle FI. Fr. 2,48. 
Diatoma marinum, Lyngbye Hydr. Ban. 180. 
On marine plants ; summer. 
Tufts small, brownish ; threads very slender ; joints as 
long or twice as long as broad. 
