288 RHODOPHYCEJS. 



with absolute certainty, but they are believed to directly develop the new 

 plant." Wood's fresh Water At gas of U.S., p. 218. 



It is somewhat uncertain what should constitute the limits of species 

 in this genus, so that, with the exception of B. atrum, we have not de- 

 parted from the most generally accepted series, although we fail to dis- 

 tinguish more decided specific characters to separate B. vac/urn from B. 

 moniliforme than can be found between, so-called, varieties of these 

 species. 



Batirachospermum moniliforme. Roth. Cat. Sot. in., 160. 



From one inch to a foot in length, clothed with a more or less 

 firm gelatinous mucous, violet-brownish, reddish-brown, purple, 

 or bluish-green, vaguely and profusely branched, joints of the 

 branches similar, oblong or clavate, outer ones sometimes seti- 

 gerous, internodes naked, or furnished with scattered accessory 

 branches. 



SIZE. Cellules -02--022 x -01 mm. 



Rabh. Alg. Eur. iii., 405. Kirch. Alg. Schles. 45. Eng. Fl. 

 v. 388. Jenuer, Tunb. Wells, 176. Eng. Bot. ii., t. 25-42. 

 Harv. Man. 119. Johust. Fl. Berw. ii., 257. Mack. Hib. 221. 

 Hass. Alg. p.. 109. Hook. Fl. Scot, ii., 77. Gray AIT. i., 330. 

 Vauch. Conf. 112, t. 1, f. 5 ; t. xi, f. 4. 



Conferva gelatinosa, Dillw. Conf. t. 32. Relh. Cant. Supp. 

 21. Hull Br. Fl. 332. Eng. Bot. i., t. 689. Huds. Ang. ii., 

 597. With. Arr.iv., 134. Lightf. Fl. Scot. 986. Sibth. Ox. 

 337. Abbot. Bedf. 275. 



Conferva fontana nodosa spermatis ranarum, Ray Syn. 62. 

 Dill. Muse. 36, t. 7, f. 42-46. 



Batrachosperma ludibunda moniliformia, Bory. Ann. des Mus. 

 xx., t. 30, f. 1. 



In streams and ditches. 



Plate CXX. fig. a, portion of filament X 30 diam. ; I, portion X 200 

 diam. 



var. setigerum. Rabh. Algce Exs. No. 854. 



The extremities of the moniliform branchlets attenuated into 

 a long setiform thread. 



SIZE. Cells -02 --024 x -01 mm. 



var. pulcherrimum. Bory. Ann. des. Mus. p. 40. 



About four inches long, violet or purple, the gelatinous in- 

 vestment less developed. Branches elongated, whorls rather 

 distant, globose, with the apices of the branchlets almost con- 

 fluent, interstitial spaces nearly naked. 



SIZE. Cellules -018 x -01--012 mm. 



Kirch. Alg. Schles, 45. Rabh. Alg. Eur. iii., 405. 

 Batrachospermum pulcherrimum, Hass. Alg. 109, t. 14, f. 1. 

 Batrachosperma ludibunda pulcherrima, Bory. loc. cit. 



