72 CONFERVACE^. 



2. Deapaenaldia glomerata^ Ag. ; frond vaguely much branched ; articulations of 

 the main stems once or twice as long as broad, swollen in the middle ; pencils of ramuli 

 alternate or scattered, often distant, ovate in outline, fasciculato-multifid. Ag. Syst. p. 

 58. .Kiitz. Sp. Alg. p. 356. Lyngh. Hyd. Dan. t. 64. Hass. Brit. Fr. W. Alg. 

 p. 120, tab. 13,/. 1. Conferva mutabilis, Dillw. Conf. t. 12. E. Bot. t. 1746. 



Hab. In clear streams. New York, Professor Bailey. Rhode Island, Mr. Olney. 

 (v. V.) 



Very similar to the last species, but less densely plumose, with scattered fascicles of 

 ramuli. 



3. Deapaenaldia plumosa, Ag.; frond very slender, elongate, much branched ; 

 joints of the main filaments once or twice as long as broad ; pencils of ramuli opposite 

 or whorled, plumose, much attenuated, pinnate or bi-pinnate, the apices of the pinnules 

 acicular. Ag. Syst. p. 58. Kiitz. Sp. Alg. p. 357. Hass. Brit. Fr. W. Alg. p. 121. 

 tab. 12,/. 1. 



Hab. In streams. West Point, Professor Bailey, (v. v.) 



More slender than D. glomerata, and much more branched, forming dense, gelatinous 

 tufts, 3-6 inches long, often much drawn out in running water. In the American 

 specimens the articulations of the stem and branches are about twice as long as broad, 

 slightly constricted at the nodes, and swollen in the middle. Several seriated cells of 

 this length follow each other, and then occur two or three short, nearly globular cells 

 consecutively, which shorter cells emit the opposite or ternary penicillate ramuli. This 

 alternation of longer and shorter cells occurs throughout the branch, the shorter ones 

 always producing the ramuli. The ramuli are pinnate or bi-pinnate, but much less 

 compound than in J), opposita or D. glomerata. 



The synonymy of this species is confused. The American plant differs slightly from 

 the European specimens with which I have compared it, but I am not disposed to fhink 

 it specifically different. Indeed the three forms now described as species are so similar 

 in all essential respects, that it may well be questioned whether they should be kept 

 separate. 



III. CLADOPHORA. KUtz. 



Filaments (not gelatinous) tufted, articulated, uniform, branched. Articulations 

 filled with green, granular endochrome, which is changed at maturity into zoospores. 

 (Marine or in fresh water. j 



An immense genus, in which, for the present, are placed almost all the branching 



