f 

 FRKSH-WATKK A L G M OF THK UN T KID STATES. 109 



Mr. Kulfs' description of tlie conjugation is as follows: The process of the con- 

 jugation in tliis specie* (litters frnin that in the rest of this genus; for, as in Hi/or 

 lutItx-,1 ,/<W< /.-, tin- conjugation cells enter into the formation of the containing 

 cell and are permanently attached to the sporangium, instead of being detached, 

 as commonly happens, in tin- l)e.>mids. The sporangium is at first cruciform, then 

 quadrate, and finally orbicular. 



P. closterioides, lUtra 



P. rrllulis anguste lanccolatis, diametro innximn 5-6 plo longioribuR, a mcdioin apices subtrun- 

 cat<>-roMimlat.is scn.-iin aticiiuutis ; laininis chlorophyll, saturate viridibus, mcdio fascia trans- 

 viTsa pullidu inti-rruptis. (K.) Species mihi ignota. 



Diam 0.00159" 0.00175". (R.) 



Syn. P. closterioides, U.M.I-.-. RABENHORST, Flora Enrop. Algarnm, Sect. III. p. 121. 



Hab. Propc Grahamsville, Sooth Carolina. Prof. Bailey. 



Cells narrowly lanceolate, 5-6 times longer than the greatest diameter, sensibly attenuate from 

 tin- initlillc into the subtruucate apices; chlorophyl lamina deep green, interrupted by a median 

 pale baud. 



Genus CLOSTERIUM, KITSCH. 



(Ylluhr intcrdum cylindricse sed siepius fusiformes ct utroque polo attenuate, plus minus lunula- 

 tim ciirvatie, in medio hand constrictae sed stria transversa unica vel 2-5 impressse. Cytioderma 

 UMIMC, -ni tirmura, leave vel plus minus distincte striatum et interdura longitudinaliter costatum. 

 r\!i"], hi-ina chlorophyllosa plerumqne in laminis longitudinalibas disposita, et sub cellulae polis 

 Im-rllo achroo, plcrumque globoso et corpusculis plus minus numerosis se vivide morentibus impleto 

 instructa. 



Cells sometimes cylindrical, but more often fusiform and attenuate at each end, more or less 

 Innately curved, in the centre not constricted but marked with from 1-5 transverse striae. Cytioderm 

 tliin, moderately firm, smooth or more or less distinctly striate, and sometimes longitudinally costate. 

 Cblorophyllous cytioplasm mostly arranged in longitudinal lamina, and furnished at each end with a 

 clear space, which is mostly globose, and contains more or less numerous actively moving corpuscles. 



a. Zygosporas globoste, rarinsime angulares ; cellulx crura attt non aid minus producta. 

 a. Zygospores globose, very rarely angular ; crura of the cells not at all, or only slightly, pro- 

 duced. 



1. Cellulte cylindrical, ad utrumque polum vix vel paullum attenuatx, recta vel leviter curvatee, 

 apicibus rotundalis vel truncatis. 



1. Cells cylindrical, not at all or but slightly attenuated at the ends, straight or slightly 

 curved, the apex rounded or truncate. 



C. -Iriolalum, EHRB. 



C. anguste lanceolato-fuBiforme, leviter arcnntnm, 8-12 plo fere longius qnam latnm, utroque 

 polo paulum sensimque attenuatum, apicibus truncatis saepe fnscoscontibus ; membrana dis- 

 tinctissime striata, vacnata fuscescente; vesicnlis chlorophyllaceis 5-7 (in qnoque crure); 

 locello apices versus sito, submagno, corpuscula 12-20 includente. (R.) 



Diam. ^,"_^"= 0.00152" 0.00187". (R.) 



Syn. C. striolalum, EHRB. RABENHORST, Flora Europ. Algarum, Sect III. p. 125. 



Ilab. In aqnis quietis, Centre County, Pennsylvania. Wood. Saco Pond, New Hampshire. 

 (Lewis) 



Narrowly lanceolately-fusiform, slightly bent, 8-12 times longer than broad, sensibly attenuated 



