1925] 8 etch ell-Gardner: MeJanophyceae 577 



terminal cell pyriform, 30-35ju, long, 18-22/x diam., with large ehroma- 

 tophores; zoosporangia obovoid to ellipsoidal, 40-50|U. long, SO-SSjit 

 broad ; hairs sparse, 4.5-5.5/* diam. 



Growing on Heterochordaria ahietina (Rupr.) S. and G. Extend- 

 ing from Cook Inlet, Alaska, to Vancouver Island. 



Setchell and Gardner, Phyc. Cont., 1894, p. 12. Mesoghia simplex 

 Saunders, Alg. Harriman Exp., 1901, p. 423, pi. 50, figs. 3, 4 ; Setchell 

 and Gardner, Alg. N.W. Amer., 1903, p. 250. 



The measurements given in the diagnosis apply to the collection 

 from Sitka. Saunders (loc. cit.) gives 25-35/* long and 15-25ju, broad 

 for the dimensions of the zoosporangia. Those in the collection of 

 Polley and Butler in the Herbarium of the University of California 

 (no. 99329) from Vancouver Island, have zoosporangia up to 80/* long. 

 Otherwise they agree well with the Sitka plants. Small immature 

 specimens of this plant were found growing on Heterochordaria 

 ahietina distributed by Miss J. E. Tilden (Amer. Alg., no. 348 sub 

 Chordaria ahietina) . 



Oobia simplex differs from Gohiu. haltica in being simple and in its 

 tendency to be somewhat enlarged above. Gol)ia simplex has always 

 been found growing on Heterochordaria ahietina S. and G. 



FAMILY 17. COILODESMACEAE fam. nov. 



Fronds membranoiLS, tubular or ligulate, growth subterminal at 

 least in early stages, possible terminal at the beginning, composed of 

 at least two tissues, inner composed of more or less elongated cells, 

 becoming smaller outwards and passing into short anticlinal filaments 

 firmly agglutinated into a cortical assimilating tissue ; zoosporangia 

 immersed in the cortical tissue but extending to, or near to, the sur- 

 face ; gametangia unknown and gametophyte presumably microscopic. 



Coilodesmeae Kjellman, in Engler und Prantl, Die natiirl. 

 Pflanzen fam., 1 Th., 2 Abt., 1893, p. 200. 



Stroemfelt (1886, p. 47) assigned his new genus CcUodesme to the 

 Chordariaceae, a.s then understood, and as an intermediate type 

 between the Chordarieae and the Scytosiphoneae. In vegetative struc- 

 ture, Coilodesme is more highly differentiated than Chordaria, in that 

 its cortical filaments have lost their distinctness and are combined 

 into a definite tissue in which the zoosporangia are immersed. The 

 method of growth has not been carefully or completely determined 

 but seems (cf. Oltmanns, 1922, p. 62, fig. 354, 2) to be subterminal. 



