460 University of California Publications in Botany [Vol. 8 



5. Myrionema corunnae f. sterile S. and G. 



Fronds forming circular cushions, 1.5-3 mm. diam. ; erect filaments 

 straight unbranched, cylindrical, blunt, 55-65/x long; true hairs and 

 "ascocysts" absent; gametangia cylindrical, blunt, on 3-5-celled 

 pedicels, rarely sessile, 55-65/a long, 4.5-5.5/* broad; gametangia and 

 sterile erect filaments diminishing in length very regularly and 

 gradually from the center to the circumference of the fronds. 



Growing on the pneumatocysts of Nereocystis Luetkeana. Cast 

 ashore. Carmel Bay, Monterey County, California. 



Setchell and Gardner, Phyc. Cont. II, 1922, p. 340, pi. 33, figs. 

 13-15. Chilionema ocellatum Collins, Holden and Setchell, Phyc. 

 Bor.-Amer. (Exsicc), no. 1739. 



This form is to be distinguished from the species as described by 

 Sauvageau (1898, pp. 77-82, repr.) by the presence of numerous 

 sterile erect filaments interspersed among the gametangia, about one- 

 fourth to one-fifth as many as the gametangia, by the absence of hairs, 

 and by the very gradual diminution in the length of the sterile fila- 

 ments and the gametangia from the center to the circumference of 

 the fronds. The sterile erect filaments are of the same length as the 

 gametangia. 



Myrionema foecundum (Stroemf.) Foslie (Orthog. mut.) 



Myrionema (Phycocelis) foecunda (Stroemf.) Foslie, New or 

 Crit. Norw. Algae, 1894, p. 17 (repr.). Phycocelis foecunda Stroem- 

 felt, in Notarisia, 1888, p. 383, pi. 3, fig. 5. 



Foslie (1894, p. 15, repr.) states, ''I have been unable to find any 

 real distinction between Myrionema, Phycocelis and Ascocyclus, 

 and therefore I consider the two latter as subgenus of the former, 

 Ascocyclus, however principally founded on the presence of para- 

 physes. " We likewise are unable to discern any fundamental dis- 

 tinctions among these three genera. Phycocelis was proposed by 

 Stroemf elt (1888, p. 383) with P. foecunda as the type. This species 

 has a unistratose base, and all of the erect filaments, except the hairs 

 and the marginal filaments, metamorphose into gametangia. These 

 are characters of typical Myrionema, as we interpret the genus. 



The genus Ascocyclus was founded by Magnus (1874, p. 73) based 

 upon J. G. Agardh's Myrionema orbiculare, which, as figured by 

 Crouan (1867, pi. 25, gen. 163), has a unistratose base, plurilocular 



