1920] Setchell-G<irdner : Phycological Contrihutians 295 



Internoretia Fryeana sp. nov. 



Plate 23, figures 3-6 



Cellulis filamentorum terminaliuni 3.5-5/* diam., 3-5-plo diam. 

 longioribiis, apicalibus conicis ; cellulis partium thallorum vetustiorum 

 isodiametricis, angularibus ; aliter ut in generi. 



Cells of the terminal filaments 3.5-5/a diam., 3-5 times as long, 

 apical cell conical ; cells of the older part of the thallus isodiametric, 

 angular; otherwise as the genus. 



Growing within the membrane of Porphyra Naiadum. Friday 

 Harbor, Washington, July. Type no. 4260, Gardner. 



This most interesting little plant is as yet known only from the 

 collections and observations of Professor T. C. Frye. It generally 

 occurs in such abundance as to discolor the host plant. In some years 

 it is very common, discoloring most of the plants of Porphyra in the 

 neighborhood of the Puget Sound Marine Station, while in other years 

 it is difficult to find any plants at all. 



Pseudulvella prostrata (Gardner) comb. nov. 



Growing on the basal portion of Iridaea laminarioides. Central 

 California (Lands End, San Francisco). 



Ulvella prostrata Gardner, New Chlorophj^ceae, 1909, p. 373, pi. 

 14, figs. 1, 2 ; Collins, Green Alg. N. A., 1909, p. 287 ; Collins, Holden 

 and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1629. 



Recent observation has revealed the presence of a pyrenoid in each 

 cell of the plant under consideration, a character not belonging to the 

 genus Ulvella. This character militates against placing it in that 

 genus. As found growing on Iridaea, it has no penetrating rhizoids, 

 thus differing in this respect from the genus Pseudopringsheimia, to 

 which it seems closely related. Nothing has yet been learned regarding 

 reproduction. Considered in the light of our present knowledge, 

 Pseudulvella seems to be the genus most appropriate for its reception. 



Pseudulvella applanata sp. nov. 



Thallo tenui parenchymatico, per incrementum marginale ad mm. 

 plura augescente, laevi et nitido, 45-55;u, crasso, laete viridi ; cellulis 

 in series verticales, proxime regulares positis, proxime isodiaraeitricis, 

 acute angulatis, 6-7. 5/a diam. ; chromatophoris parietem cellularum 

 tegentibus, pyreuoidibus singulis; zoosporangiis (?) e cellulis super- 

 ficialibus leviter transformatis oriundis; generatione ignota. 



Thallus thin, parenchymatous, spreading by marginal growth, ex- 

 panded to several mm. in diam., smooth and glossy, 45-55/a thick ; 

 color grass green ; cells in fairly regular vertical rows nearly isodia- 



