194 .,„!.; '. ;,Rllodora [October 



tlie last cell of the branch is ot" about the same size as the preceding 

 cells, and the much more slender hair is sharply distinct from it. 



Forma luxurians (J. Ag.) n. comb.; Calliihamnion luxurians 

 J. G. Agardh, Species Algaruui, \o\. II, p. 14; Harvey, Nereis 

 Bor.-Am., part 2, p. 242; Tirntcpohlia virgatula var. seciuidata 

 Farlow, N. E. Marine Algae, p. 109; Chaniransia t'irgatuJa Farlow, 

 Anderson & Eaton, Alg. Am.-Bor. Exsicc, No. 157. Instead of 

 isolated tufts, this form occurs as an uniform continuous fringe on the 

 edge, rarely on the surface of Zostera marina L.; the basal disk 

 practically continuous. Gloucester, Mass., to Bridgeport, Conn. 



Forma tenuissima (Collins) n. comb.; Chaniransia virgatula 

 forma tenuissima Collins, P. B.-A., No. 741. Filaments arising 

 from a small disk, about S fi diam. at base, cells about 3 diam. long; 

 branches sometimes frequent near base, infrecpient above, often in- 

 frequent throughout; long and virgate, gradually ta])ering to about 

 4 /(, with cells 8-10 diam. long, not ending in hairs; spores S X 20 n, 

 sessile or on a one-celled pedicel, scattered or in short secund series. 

 On Zostera, San Pedro, California, Nov., 1898. 



A. Daviesii (Dillw.) Niigeli, Mori)h. & Syst. tier Ceraniiaceae, 

 p. 412; Conferva Daviesii Dillwvn, British Confervae, p, 73; Calli- 

 thamnion Daviesii Harvey, Nereis Bor.-Am., part 2, p, 243; Trente- 

 pohlia Daviesii Farlow, N. E. Marine Algae, p. 109; Chantransia 

 Daviesii P. B.-A., No. 880. Base a small cellular disk, one layer 

 thick, bearing several filaments, about 10-12 a diam. near base, not 

 much smaller upwards; branches abundant, largely secund, rather 

 erect; cells 2-4 diam. long; s])ores 10-12 X 15-20 /(, sessile or on 

 short pedicels in close series on the upper side of the branches at their 

 base; hairs more or less abundant. Forming fringes along the edge 

 of Rliodi/inenia palmafa (L.) Grev., and occasionally on other algae. 



The arrangement of the spores in this species distinguishes it from 

 all others except A. Sagraeaninn, which has a different basal portion. 



A. SECUNDATUM (Lyugb.) Niigeli, 1. c, ]). 414; CaUiihavinion 

 Daviesii var. secundatum Lyngbye, Hydr. Dan., p. 129; Chantransia 

 secundata P. B.-A., No. 1088, not 236. Base a cellular disk, usually 

 two layers thick; filaments several from the same disk, 9-12 ,« diam. 

 below, simple for a short distance, then densely branched, branches 

 rather patent, long and short intermixed, at first secund, later often 

 opposite, 6-8 ,« diam. near the end, which often bears a hair; cells 1^- 

 2 diam. long in main filaments, 2-3 in the branches; spores 10 X 18 n, 



