72 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



vegetative portion of the thallus generally dies away, and 

 these branches become fixed by rhizoids of their own. The 

 fructiferous branches are long, filamentous, cartilaginous, and 

 swing freely in the water; they are olive-green or greenish 

 black. Each thread is built up of an axile row of tubular 

 cells surrounded by rows of smaller cells ; at short, more or 

 less regular, distances along the entire length are distinct 

 swellings or nodes. 



Only sexual multiplication is known. The antheridia are 

 short and cylindrical, growing on whorled eminences or on the 

 widest part of the nodes. The carpogonium possesses a long, 

 simple or branched process for the reception of the male 

 gamete, called a trichogyne. After fertilization the car- 

 pogonium puts out an ooblastema-filament, at the extremity 

 of which a bunch of jointed moniliform filaments arises, each 

 of the swollen cells of which becomes at maturity a carpo- 

 spore. The carpospores are produced on the inside of the 

 thallus, filling up the space between the axile cells and the 

 cortical cells. The carpospores in turn produce the vegetative 

 thallus. 



Lemanea Bory. Large, simple or somewhat branched, 

 bristle-like threads of drrk or brownish color; hollow except 

 for the axile series of cells which is held in place by transverse 

 threads at regular intervals. 



[L. fucina var. rigida (Sirdt.) Atk.] 



Tuomeya Harvey. Thallus much branched, upright, 

 five cm. high, rosette-like. 



[T. Hiiviatilis Harvey.] 



FAMILY II. HELMINTHOCLADIACE.E. 



The plants consist of a filamentous thallus, simple or 

 branched, with the secondary axes often arranged in whorls. 

 The main filament may consist of a single row of cells or of an 

 axile row surrounded by cortical rows of smaller cells. 



The terminal cells of the gonimoblasts, which are short 

 tufts of filaments, generally form the carpospores. When the 

 carpospore has become detached, the supporting cell grows 

 through the old cell wall and produces a new spore-forming 

 cell. The cystocarp has no. definite wall. 



