i*^-5J Setchell-Gardner : MeJanophyceae 467 



14, Mjnrionema compsonematoides S. and G. 

 Plate 55, fig. 10 



Fronds forming microscopic cushions irregular in outline, 200-400/a 

 diam., prostrate portion composed of distorted filaments; erect fila- 

 ments cylindrical, unbranched, 70-80ju, high ; hairs unknown ; cells of 

 creeping filaments considerably irregular in shape and size, 4-6jli diam. ; 

 cells of erect filaments cylindrical, 5-7jli diam., quadrate; "ascocysts" 

 sparse, terminal or at times lateral near the base of the erect filaments ; 

 gametangia fusiform to clavate, sessile or short-pedicellate, 50-65/x 

 long, 7-lOja broad ; loculi uniseriate below, biseriate above. 



Growing on the blade of Laminaria complanata. Friday Harbor, 

 Washington. 



Setchell and Gardner, Phyc. Cont. II, 1922, p. 343, pi. 34, fig. 10. 



Myrionema rompsonematoides seems to be a modification of M. 

 faecundum. There is a slight sterilization of tissue in that a few of 

 the erect filaments remain sterile and develop slightly beyond the 

 gametangia, and in that a part of the gametangia are pedicellate. It 

 seems to tend toward Compsonema in these respects, and in having 

 biseriate gametangia in part. 



15. Myrionema hecatonematoides S. and G. 



Plate 55, fig. 11 



Fronds forming thin light brown cushions, more or less circular 

 in outline, up to 6 mm. diam. ; prostrate portion composed of distorted, 

 irregularly radiating filaments, mostly monostromatic, in part distro- 

 matic, producing a few penetrating peg-like rhizoids below ; erect 

 filaments unbranched, cylindrical, 240-260ju, long ; true hairs absent ; 

 cells of erect filaments 6.5-7.5/a diam., 2-3 times as long; zoosporangia 

 unknown ; gametangia sessile or on 1-2-celled pedicels on the creeping 

 filaments, cylindrical to fusiform, 45-55ju, long, 7-8. 5/a broad ; loculi 

 mostly uniseriate, biseriate in widest part of the gametangia. 



Growing on thepneumatocysts of Nereocystis Liietkeana. Pacific 

 Grove, California. 



Setchell and Gardner, Phyc. Cont. II, 1922, p. 343, pi. 34, fig. 11. 



As indicated by the partially distromatic base, the slight tendency 

 to biseriate loculi in the gametangia, and the sterilization of a part 

 of the erect filaments, this species of Myrionema seems to be differen- 

 tiating in the direction of the genus Hecatonema. We are retaining 



