THE GREEN ALGAE OP NORTH AMERICA 355 



pata forma subsimplcx Collins. It is quite close to forma longis- 

 sima (Kiitz.) Rabenhorst, 1868, p. 337. This form seems to be 

 quite common in California ; the fronds remaining attached to 

 stones, etc. in running water until they have reached their full 

 growth, sometimes as much as a meter ; the branching is rather 

 distant, the ramuli are short, with cells 4-8 diam. long. 



50. C. SECUNDA Kiitzing, 1849, p. 411; P. B.-A., No. 

 1230. Forming dense masses; main filaments elongate, sinu- 

 ous, sparingly branched alternately or subdichotomously ; bear- 

 ing long secund series of ramuli, normally one from each cell of 

 the filament ; long below, becoming gradually shorter towards 

 the tip ; cells in main filaments and branches 90-125 fj. diam., 

 3-5 diam long, cylindrical or somewhat contorted ; in ramuli 

 20-40 /u. diam., 4-8 diam long, cylindrical or slightly swollen ; 

 ramuli tapering to the subacute tip. California. Europe. 



No authentic specimen of this species being accessible, there 

 is naturally some doubt as to the identification ; the Californian 

 plant formed floating masses in a watering trough at No. Berke- 

 ley, Cal., while Kiitzing's plant, though included by him among 

 the fresh w r ater algae, was found by Suhr in brackish water in 

 Denmark. The description agrees well with the plant, and 

 there seems to be no other described species in which the latter 

 could be included ; to avoid making a new species, the present 

 name is applied. In our plant there is a remarkable contrast 

 between the coarse cells of the large filaments and the delicate 

 cells of the ramuli ; it seems like young plants of C. crispata 

 growing out of old, battered stems of C.fracta, and emphasizes 

 our lack of knowledge of any of these species, through all their 

 life history. 



51. C. INSIGNIS (Ag.) Kiitzing, 1845, p. 217; 1854, PL 

 XXXVIII, fig. i ; P. B.-A., No. 868. Forming extensive 

 strata ; filaments straight or nearly so, usually very little 

 branched, 75-120 /A diam.; branches down to 40 /u, diam.; cells 

 4-6 diam. long, somewhat swollen. In quiet \vater, California. 



Europe. 



Fairly distinct by the stout, straight, little branched filaments. 

 Our plant seems to belong to the type, but any of the numerous 

 varieties may be expected. 



52. C. HOLSATICA Kiitzing, 1849, p. 414; C. a eg agropUa P. 

 B.-A., No. 164. Forming by the dense and irregular branch- 



