1 UKSII-WATER ALGJ-l OF TUB UNITED STATES. 143 



Diam. 0.0047". Long. 0.0039". (R.) 



;i . M. oxctianK, HALTS, British Dcsmidicte, p. 76. RABENHORST, Flora Europ. Algarum, 



Sect. III. p. 119. 

 M. pinnatijida KTZ. RABENUORST, Flora Europ. Algarum, Sect III. p. 119. 



Hub. Florida ; Rhode Island ; Bailey. 



Frond about aa broad as long, pinnatifid; lateral lobes separated from the terminal by a rounded 

 sinus, horizontal, conical, their extremities bidentate ; end lobe short, broad, its lateral pro- 

 jections short, conical, usually bidentatc, narrower and shorter than the lateral lobes; ends 

 uves at the centre; tr. v. fusiform, e. f. punctate. (A.) 



/,'- niarktt. According to Prof. Rubenhorst M. pinnatifida, Ktz., is a variety of M. 

 otcilans, different from the typical form only in being smaller, and in having the 

 lobes narrower. 



Ji. SemieeUulte 3-vel b-lobae, plerumque rodiotim inciso-lobulotte. Lobi boaales assurgentes 

 out non out minus a lobo polari remoli. 



B. SemicelU 3, or b-lobate, mostly radiately innsely tabulate. Basal lobes assurgent, either 

 close to, or but slightly remote from the end lobes. 



* Semicellula: trilobte. 



* Semicells trilobate. 



n. Americana, (EHRB.) KTZ. 



M. nmgna, oblonga, snbpinnatiseeta, lobis polaribns paulam remotis, psene duplo longior qimm 

 luta ; cytiodermate spinuloso unde laborum rnargines dentato-serrati conspiciuntur ; cellula 

 e latere conspecta oblonga, in medio leviter constricta. utroque polo bicornuta ; semicellulee 

 liasi tumore plus minus distincto instructs, fere quinquelobae, lobis basales latitssimi iisderaque 

 profunde bilobati, lobulis late excisis, segment is dentato-serratis ; lobis polaribus plus minus 

 productis, in medio late excisis, scgmentis profunde bifidis. (R.) 



/>/m. 0.0041". Long, circa 0.0051". (R.) 



n. M. Americana, KUTZIXO. RABENHORST, Flora Europ. Algarum, Sect. III. p. 189. 

 h. In stagnis, South Carolina; Florida; Bailey. 



Frond angular elliptic, more or less punctate ; segments 3-lobed ; lateral lobes broad, cuneate, 

 ilicir margins concave, ineiso-serrate ; and lobe broad, cuneate, end exserted, bipartite at the 

 angles, the subdivisions narrow, and minutely dentate at the extremities; end concave. (A.) 



Remark. Fig. 17, pi. 12, represents a plate of this species. 



M. Baileyi, RALFS. 



M. ]>:irvn, oblonga, granulata; semiocllulia trilobis, lobis basalibns a lobo polari sinn amplo 

 discretis, excisnra acute triangular! in duas lacinias partitis, laciniis e basi latiori in apicem 

 truncatum bidentatum attenuatis; lobo polari e basi angnsta longe porrecto, snrsum valde 

 dilatato, in rertice leviter et late sinnato, angulis truncate, bidentato. (R.) 



S'yn. M. Baileyi, HAI.FS. British Desmidieae, p. 211. 



ffab. New York; Rhode Island ; South Carolina; Florida; Bailey. 



Frond granulated ; segments three-lobed ; lobes bipartite, end one much exserted. (Ralfs.) 



!H. rin^ens, BAILET. 



M. inediocris, oblonga, margine grannlata; semicellnlis trilobis; lobis lateralibns bipartitia, 

 laciniis divaricatis, apjce obtnsis, trnncatis yel bidentatis; lobo polari e basi angusta sursum 

 valde dilatato, exserto, in vcrtice leniter sinuato, angulis truncate. (R.) 



