Synopsis, continued from page 9 (and completing the "Macrodactylte" group.) 



! ! DIFFUSA, fertile verticils not contracted '< in dense axillary and terminal 

 masses." N. Leibergi, Allen. 



X X FLABELLATAE folise twice or more divided. 



GYMNOCARPAE.* 



1. Fruit in all divisions of the leaves, the last division sometimes excepted. 



-(- Cospore (nucleus) 270 to 380 long. N. mucronata, A. Br. 



-j- -)- Oospore 220 to 280 long. 



a, with five ridges, prominent. N. capitellata, A. Br. 



b, with six ridges, not prominent. N. gracilis (Smith), Ag. 



c, with seven or eight ridges, prominent. N. transilis, A. 



2. Fruit in all divisions of the leaves, except the first division, which is sterile, 



usually. 



a, folise as long as or longer than the internodes, spreading. 



N. transilis, A. 



b, folia short, verticils compact, often moniliform. 



N. tenuissima (Desv.) Kiitz. 

 * * GLOEOCARPAE. Fruit enveloped in mucous. 



1. Plants minute, stem 130 in diam. N. minuta, A. 



2. Plants larger. 



a. Diffusa, stem 300 to 450. N. intermedia, Nordst. 



b. Congest a, stem 400 to 750. N. Asa-Graeana, Schaffner. 



NITELLA LEIBERGI, sp. nov. Nilella, diarthrodactyla, homoeophylla, 

 monoica, macrodactyla, sub-flabellata (furcata) gymnocarpa, diffusa. 



Plants small, 3 to 4 cm. in height, diffusely branched. Stem 400 

 to 425 in diam. Verticils consist of six "leaves." The leaves, often 

 heteromorphous (some simple undivided, others divided) once or 

 twice divided ; first segment 340 to 360 in diam. ; first node, rarely fer- 

 tile ; second segment 220 to 268 in diam; second node usually fertile; 

 third (terminal) segment 164 to 176 (125 to 135) in diam. ; two celled. 

 Terminal segments are usually four in number, as a rule undivided, but 

 at times part or all of the terminals are again divided, the extra node 

 bearing in turn four terminals. The ultimate cell, a mucro, is about 50 

 in diam. at the base, by 175 (135 to 185) long. The penultimate cell 

 generally tapers somewhat from about its middle to the base of the mucro. 



The antheridia are about 225 in diam. (vary from 200 to 300). 

 The oogonia are isolated about 390 long, including the small and per- 

 sistent coronula. The oospore (nucleus) averages 272 long by 175 to 

 240 broad, with six strong ridges; its surface is marked with fine gran- 



