Ponds; August. P 
Tufis thick, dark green, floating; threads as thick as a 
horse-hair ; ¢ransyerse tubes very short. 
XVII. 17.CHOASPIS. ei enis. 
Thallus threadlike, simple, tubular, jointed, kneebent; 
coupling at the bend, by a perforation in each joint, which 
4ransmits the granules from one plant to the other, where 
they form an elliptic spore; granules scattered. — Not 
slippery. 
Choaspis serpentina. Serpentine choaspis. 
Threads slender, stiff, here and there slightly bent, and 
coupling; joins four times as long as broad; granules in a 
triple irregular series. 
Conferva stictica, Engl. Bot. 2463. 
Ditches. 
Tufts floating, pale yellowish green above, blackish 
green beneath; joznts when young pale green. 
XVIII. 18. AGARDHIA. Agardh. 
Thallus threadlike, simple, tubular, jointed, bent, ap- 
proximating and uniting here and.there with others, the 
coupled joints becoming shortened; granules in a single 
dine, spore formed in the shortened coupled joints, .cross- 
shape.— Bluish green. 
Agardhia cerulescens. Bluish agardh. 
Threads slender, bent, light purplish blue; joints 6 times 
as long.as broad; granules and spores greenish. 
Conterva cerulescens, Engl. Bot. 2457, 
Conferva conjugata, dgardh Syn. 96. 
. Conferva Agardhiana, Wall. in Liljebl. Sv. Fl.ed. 3. 
Zygnema? czrulescens, 4gardh Disp. ed. 2, 32. 
Boggy pools; July. ey’ ' : 
Joints pellucid with a central, slightly spiral, dotted line 
of green granules. 
XIX. 19. SERPENTINARIA. Serpentinare. 
Thallus threadlike, simple, tubular, jointed, knee-bent, 
coupling at the bend, by a short transverse tube coming 
from the middle of the joints, which receives the granules 
from.each plant, and thus forms a globular spore remain- 
ing in the middleof the transverse tube; granules.scattered. 
' —Slippery,. 
