128 FRESH-WATER ALG^ OF THE UNITED STATES, 



a verv brotul neck. I have never seen the sporangia, but, according to Mr. Ealfs, 

 they are orbicular and inclosed in a granulated cell. 



Fio-. 8, pi. 21, represents half of an empty frond of this species magnified 750 

 diameters; and fig. 21, pi. xii., a frond densely filled with living endochrome 



C Bofrylis, (Bory) Mengh. 



C. late ovale, profiinde constrictum, diametro plerumque 1^ — 2 plo longius ; sinu angusto, 

 liueare- scmicellulis noimibil triaugularibus, apice iuterduui truncatis, interduni late rotun- 

 datis ; cytiodermatc miuute granulato. 

 Z>iawi.—5Jf" = 0.0019" (O.OOU"— 0.0023"). (R.) 



Syn, C. Botrytis, (Boey) Menegheni. RABENnoBST, Flora Europ. Algarum, Sect. III. p. 



158. • 



Ifab. — Pennsylvania, Wood. 



C. broadly oval, profoundly constricted, 1^-2 times longer than broad; sinus narrow, linear; 

 semicells soraewluit triangular, with the apex sometimes truncate, sometimes broadly rounded; 

 cytioderm minutely granulate. 



Remarls. — In this species the semicells, as viewed transversely, are broadly 

 elliptic in outline. The end view presents a longer narrower ellipse. Their out- 

 line, wlien seen from the front, varies remarkably from that of a very broad semi- 

 oval to distinctly triangular with a truncate apex. The grannies are small and 

 arranged regularly, sometimes they are very obscure. I have often seen the endo- 

 chrome so arranged as to leave a large pyriform central vacuole in each cell, com- 

 municatinor with the narrow marjjin between it and the cell-wall. This vacuole 

 was apparently filled with a transparent fluid, in which were minute granules in 

 immense numbers, in constant active motion circling among one another and pass- 

 ing out, into and along the marginal connecting space. According to Ralfs, the 

 sporangia of this species are large {j^^"), with branched spines. 



Fig. 5, pi. 21, represents an empty frond of this species; 5 a, outlines of semi- 

 cells to show the variations, and fig. 14, pi. 12, represents a frond crowded Avith 

 endochrome, magnified 460 diameters. 



C. ovale, PvALFs. 



C. magnum, ovale, compressnm, profunde constrietum, diametro subduplo longius, ambitu inte- 

 gcrrimuni vel crenatura, a vertice late ellipticum ; semicellulis basi paulo latioribus quam 

 longis, triangulo-rotundatis, disco punctatis, margine verrucis margaritaceis achrois hyaliuis 

 in series 4 ordiuatis. (R.) 



iJt'am.— Long. 0.0053"— COOGt". Lat. plcrumque 0.0041". (R.) 



Sijn.— C. ovale, Ralfs, British Desmidieoe, p. 98. 



/7a6.— South Carolina ; Rhode Island ; Bailey. Cobble Mountain, Pa. (Lewis) Wood. 



Frond very large, elliptic, nearly twice as long as broad, constriction very deep, linear; seg- 

 ments somewhat broader than long, somewhat triangular, rounded at ends, rough near the 

 margin, with a band of large pearly granules, producing a dentate appearance, the disc punc- 

 tate ; e. V. elliptic. (A.) 



C Brcbii^sonii, Menegh. 



C. paulo longius quam latum ; semicellulis semicircularibus, diametro paulo longioribus, angulis 

 infenonbus obtusis approximatis, ventre modice concavis subplanis, dorso latissime rotun- 

 datis; cytiodermatc muricato, muricibu.s conicis in ordinibu.s regularibus collocatis. (R.) 



