This delicate and pretty plant was first sent to me from 

 Crater Lake. Mt. Agassiz, gathered by U. S. Geol. Survey. 



Later by Mr. Williams from Sand Coulee, Montana. 



Explanation of Plate. i, plant natural size ; 2, male plant, x 25 ; 

 3, female plant, x 25 ; 43 mature oospore, x 50 ; 5, a portion of 

 the finely granulated membrane of the spore highly magnified. 



NITELLA BLANKINSHIPII, Sp. nov. Monarthrodactyla, fureata, 

 homxophylla (rarius heterophylla\ dioica gymnocarpa, acuminata. 



Plant delicate, not over 5-10 cm. high, branched above. 

 Leaves eight in a verticil, once divided, all similar, except in 

 rare instances heterophyllous (see figure 2) ; leaves with very 

 thin walls, with a slight tendency to become dilated ; first segment 

 300 //. in diam. ; terminal segments, two to four, 150 /.i. in diam. 

 Oogonia usually single ; coronula, persistent ; oospore, 450 //. 

 long; 400 //. broad, with 6 (to 7) sharp and prominent ridges; 

 membrane of the spore roughened by scattered granules not uni- 

 form in size (of uniform size in N. Montana). Antheridia, 600 

 //. in diam. 



This little nitella was gathered in Missouri by Mr. Blankin- 

 ship (an enthusiastic collector of characeae) ; it has been found 

 only in one locality. 



It is interesting to observe the occasional variation of hetero- 

 phyllous leaves, since in other respects it bears some resem- 

 blance to N. clavata of the Pacific coast; this species, however, is 

 separated from that by being dioecious and commonly homceo- 

 phyllous. 



Explanation of Plate. i, plant, natural size ; 2, two verticils 

 showing different sorts of leaves (rare) ; 3, an ordinary sterile 

 verticil ; 4, an antheridium ; 5, an oogonium separated from its 

 leaf ; 6, oospore ; 7, membrane of oospore highly magnified. 

 Figs. 2, 3 and 4 magnified 25 diam, figs. 5 and 6 mag. 50 diam. 



NITELLA MISSOURIENSIS, N. SP. Plant diffusely branched 

 15-20 em. in length, in size and appearance resembling opaca, or, 

 still more, subcapitata ; to the latter it would be unhesitatingly 

 referred, except for the fact of being entirely devoid of a gelatinous 

 envelope about the fruit. Mature spores have not been gathered, 

 and their characters and markings cannot be noted ; the coronula 

 of the oogonium seems to be persistent (as usual in the section 

 " acuminate"} the ridges on the spore few (5). Antheridia 650 

 IA. in diameter. The two (only) specimens found were gathered 

 in April (season of subcaptata), near Springfield, Missouri, by 



