PRESH-U' ATER A L ^E OF THE UNITED STATES. 213 



able to identify tin-in. One of the forms ,TO\VS in this immediate locality, and is very 

 probably ('. .V//AI/U, Hroh. The other was collected in Northern Michigan. It is 

 charaeteri/.ed l>y its frond never being disciform, although composed of a single 

 plane of cells parenchematously united. 



CLASS KIIOIH'I'IM < i: I . 



Alga} multicclliilarcs, vegctatioue terminalis non liuiitata pra}dita3 

 plrnimqiie trioiea 1 . 



Thallus c cell iihi rum serielms vel stratis singulis vel pluribus compo- 

 situs, uut niidus aut e ccllularuin strato corticatus, forma quarn maxime 

 vaiius; int'inbranaceiis (Porphyridium), crustaceus (Hildenbrandtia), 

 tilaiiicnloHis et verticillatim raiuosus (Batrachospermuin, Thorea), fascii- 

 formis (Bangia), foliacetis, etc. 



C\ til-plasma ]>l<Tinn<iuo rhodophyllo (Colm), rarius phycho-cbromatc 

 coloi at urn, granula amyloidea vel amylacea et sajpc guttulas oleosas 

 includens. 



Propau-ationis organa triplicis indolis, saepissime in plantas distinctas 

 disjxisita. 



1. (h-ijnna mascula vel anflicrida e fasciculis celhirartim plenimque mo- 

 nilifonniluis ramosis, denique in Rpermatozoidea vel spermatia fo;ciin- 

 dantia (Sporidia I. Ag.) oblonga vel ovalia, achrod, iniiuobilia dissolutis 

 formata. 



2. Oruttnafeminca vel cystocarpia Ktz. e soris nonnunquam monilifor- 

 miluis iumiata, qui e placenta saepissime corticali evolvuntur, nudi vel 

 nitiriila inucilaginosa vel involucre inclusi, denique sporas (j)dysporas} 

 niinierosas iinuiobiles mox germinantes emittimt. Foecundatur cysto- 

 carpiiim statu priuiordiali ope organi piliformis (triclioyyHe Thuret et 

 Bonu-t) quorum spermatia copulantur. 



3. Ti-ti-tix/>orfinf/ia e cellula corticali unica valde intumescente formata, 

 <ln isione utriculi primordialis cruciata quadrilocularia ; in quoque loculo 

 (<<// H/I'S secundart'is, sororiis) spora unica (tctrasjwra) Be format, quae sine 

 foecundatione geruiinat. (R.) 



Multicellular algae, mostly trisecious, furnished with unlimited not ter- 

 minal vegetation. 



Thallus composed of cells in rows or in a simple or multiple stratum, 

 cither bare or provided with cortical strata of cells, exceedingly various 

 in form; mcmbranaceous (Fophyridium), crustaceous (Hildenbrandtia), 

 filamentous and verticillately branched (Batrachospermum, Thorea), 

 laM-iate (Bangia), foliaceous, &c. 



Cytioplasm mostly rhodophyllous, rarely phycochromatously colored, 

 including amyloid granules or starch and frequently oil drops. 



Propagation by means of three iminotile organs, generally placed 

 upon distinct plants. 



1. Antheridia composed of mostly moniliformly branched fascicles of 



