~$00 19. Serpent. 1. HYDROPHYT. Pl. cell. aph. 
1. Serpentinaria compressa. Compressed serpentinare. 
Threads brittle, bent, coupling; joints three times as long 
as broad; granules in a compressed mass. 
Conferva serpentina, Muller N. Act. Petr. 3. 
Conjugata serpentina, Faucher, 81. 
Conferva genuflexa, Dillwyn Intr. 18. 
Zygnema compressum, Lyngbye Hydr. Dan. 171. 
Stagnant waters. 
Threads as fine as human hair, very brittle; spore glo- 
bular, in the transverse tube. 
2. Serpentina genuflexa. Knee-lent serpentinare. 
Threads brittle, knee-bent, coupling; joints four times as 
long as broad, half filled with granules. 
Conjugata angulata, Vaucher, 79. 
Conferva senuflexa, Roth Cat. 2,199; Engl. Bot, 1914, 
Conferva serpentina, Muller N. Act. Peir. 3,92. 
Conjugata genuflexa, 4gardh Disp. ed. 1, 28. 
Zygnema genuflexum, dgardh Syn, 98. 
Ditches and stagnant waters; spring and autumn. 
Tufis dense, floating; threads as thick as human hair, 
slightly curved or knee-bent; grauu/es entirely or half filling 
the joints; spore globular, in the transverse tube. 
G. Hypropictyoniprx. Thallus cylindrical, thread- 
shape, tubular, jointed, anastomosing like a net; meshes 
many-sided, each side formed of a single joint; spore ? or 
embriv? like the parent, reticulated, contained with the 
joints. 
XX. 20. HYDRODICTYON. Roth. Water-net. 
Threads jointed, membranaceous, woven into the form 
of a purse-net ; spore? same form as the parent plant, en- 
closed in each joint.—Fresh-water; green. 
HAydrodictyon utriculatum. Bottle water-net. 
Threads united into a tubular net. 
Conferva reticulata, Raii Syn, 59,10; Lin. Sp. Pl. 1635; Engl. Bot. 
1687. 
Hydrodictyon utriculatum, Roth Fl. Germ. 3, 531. 
Hydrodictyon pentagonum, Faucher, 88. 
Hydrodictyon majus, Roth Cat, 2, 238. 
Hydrodictyon tenellum, Roth Cat. 2,239. 
Stagnant, or slightly flowing waters; annual. 
Plant forms a dense stratum, floating, from 2 inches to 
2 feet long; meshes mostly 5-sided, rarely 4 or 6-sided. 
