12 FRESH-WATER ALG^ OF THE UNITED STATES. 



Syn.C. multicoloratus, WOOD, Prodromus, Proc. Amer. Philos. Soc., 1869, 122. 



Hab.in rupibus humidis prope Philadelphia. 



C. occurring scattered in a mucous stratum with other algae; cells spherical and single, or else 

 angular semi-spherical or irregular and associated together in oblong families of from 2-4 

 (rarely 8) ; inner coat thick, hyaline, not lamellate ; outer coat generally wanting, sometimes 

 indistinctly present; endochrome mostly homogeneous, sometimes minutely granular, either a 

 yellowish-green or bluish-green, or yellowish or brown, or blackish, sometimes tinged with 

 bright lake. 



The cells of this species do not appear to have any tendency to unite to form 

 large masses or fronds. On the contrary they are generally very distinct. Their 

 color varies very much, in a larger number of instances they were a decided yellow- 

 ish-green, tinged at some point or other with a beautiful lake. When several cells 

 are formed by division out of one cell, a similar division of the very thick surround- 

 ing gelatinous coat follows separating them finally entirely one from the other. I 

 have seen a single cell which appears to be an encysted form of this, of which I give 

 a drawing. 



Fig. 6, pi. 5, represents different forms of this species magnified 260 diameters. 



C. thermophilns, WOOD. 



C. cellulis singulis aut geminis vel quadrigeminis et in familias consociatis, oblongis vcl sub- 

 globosis, interdum angulosis, haud stratum mucosum formantibus; tegumento crassissimo, 

 achroo, haud lamelloso, homogeneo ; cytioplasmate viride, interdum subtiliter granulato, inter- 

 dum homogeneo. 



Diam. Cellulse singulse sine tegumento longitudo maxima T ^ T '', latitude maxima ^V^"- 



Syn. C. thermophilus, WOOD, American Journal Science and Arts, 18G9. 



Hob. Benton Springs, Owen Co., California (Mrs. Parz.). 



Cells single, geminate, or quadrigeminate and consociated into families, oblong or subglobose, 

 sometimes angular, not forming a mucous stratum ; tegument very thick, transparent, not 

 lamellate, homogeneous ; cytioplasm green, sometimes minutely granulate, sometimes homo- 

 geneous. 



RemarTcs. Remarks upon this species will be found under the head of Nostoc 

 calidarium, Wood. 



Genus GLOEOCAPSA, KTZ. 



" Cellulae sphericae aut singulse aut numerosse in familias consociatse ; singular tegumento vesiculi- 

 forme (cytiodermate tumido) inclusae, post divisionem spontaneam in cellulas duas filialcs factam 

 ntraque tegumento se induit, dam ambae tegumento matricali involute remanent; cellularum harum 

 filialium iterum in duas cellulas divisione continuo repetita, tegumentnm atavise restat et sese exten- 

 dens familiam totam circumvelat. Cytioderma crassnm, saepe crassissimum, cellules lumen crassitie 

 sequans vel superans, achromaticum vel coloratura, plerumque lamellosum ; lamellae vel strata non 

 raro discedentia. Cytioplasma aeruginosum, cseruleo-viride, chalybeum, rufescens, luteo-fuscum, &c. 

 Cellularum divisio directione ad tres dirnensiones alternante. Cellulae generationum ultiuiarum 

 minores quam priorum sunt." (Rab.) 



Syn. Olobulina et Bichatia, TURPIN, ex part. 

 Gloeocapsa, KTZ., ex part. 

 Microcystis, MENEGH., ex part. 



Cells spherical, either single or associated in numbers into families; the single cell included a 

 vesiculiform tegument (the tumid cytiodcrm); this cell then undergoing division into two daughter- 



