152 American Quarterly Microscopical Journal. 



C.fracta, Ktz. Branches scattered, spread out or bent 

 backwards. Cells smooth, o.i d. Common in standing 

 water, forming so called " meteoric paper " when the 

 ponds in which it is abundant become dried up. [In 

 salt, brackish, and fresh water.] 



C. crispata, Ktz. Cells striped, otherwise like preceding. 



C. gossypium, Ktz. Cells cylindrical, 0.02-0.03 d, L = 4-6 d, 

 forms stiff or motionless dirty masses. 



C. glomerata, Ktz. Branches tufted, bushy, much branched, 

 not grown together at the base. Attached in long, flow- 

 ing filaments. 



C. canalicularis, Ktz. Like the preceding, but branches grow- 

 ing together at the base. 



4. Gen. Rhizoclonium, Ktz. Jointed filaments as in conferva, 

 but with scattered, root-like young shoots. Only known 

 sterile. 



Rh. rivulare, Ktz. Bright green. In brooks. 



\^Rh. ripariiim, Roth. Filaments long, slender, pale-green, angularly 



bent, furnished with root-like processes at the angles.] 



IV. FAMILY. ULOTRICHE.^. 

 Filaments of very different forms, with chlorophyll evenly distributed. 

 Cells broad as long. 



I. Gen. Ulotrix, Ktz. Not branched, very short, jointed fila- 

 ments; several, often many, swarm-spores form in the cells, 

 and issue through the walls, often already germinating. 

 Numerous forms, difficult to determine, generally of a 

 bright green color. 

 U. tenerri?tia, Ktz. Cells 0.008 d.and 1. 

 U. zo/tata, Ktz. Cells 0.025 ^- ^"^ 1- ^'^^ fruiting, constricted 



somewhat at the ends. 

 U. mucosa, Th. Cells 0.015-0.02. Half as long up to the same 

 length. 

 Here belong some very distinct forms living out of water : 

 Hormidium, Ktz. {niurale, and others) and Sc/iizogonium, Ktz., 

 which form the familiar green coverings on tree-trunks, board 

 fences, etc. 



V. FAMILY. CEDOGONIACE.E. 

 Jointed filaments with dissimilar cells.. Many produce from their 

 entire contents a single broad egg-shaped swarm-spore, with a crown 

 of cilia on the tapering end, which, on germinating produces a root- 

 like growth. Other cells produce several small (male) swarm-spores, 

 still others expand into spherical oogonia, to which the androspores 



