1925] Setchell-Gardner: Melanophyceae 499 



larger in thickness, are more spongy, lighter colored and have very 

 decidedly larger zoosporangia and longer paraphyses than that 

 species. The exact southern limits of either of these species has not 

 been determined. 



5. Ralfsia fungiformis (Gunn.) S. and G. 



Thallus licheniforni, coriaceous, dark brown in color, black on 

 drjdng, loosely attached in the center by numerous multicellular 

 rhizoids, free around the margin, with free overlapping lobes seemingly 

 from the top of the thallus as well as the margin, circular to irregular 

 in outline, with concentric zones and radiating striae, 2-6 cm. diam., 

 250-300/x thick ; cells forming rows curving upward and downward 

 from a central layer in the lobes ; zoosporangia, gametaiigia and hairs 

 unknown. 



Growing on rocks in the lower littoral belt. Port Clarence to 

 Sitka, Alaska. 



Setchell and Gardner, Pliyc. Cont., VII, 1924, p. 11. Fu-cus fungi- 

 formis Guimerus, Fl. Norv., 1772, p. 107 ; (Eder in Flora Dan., 1770, 

 pi. 420. Ralfsia deusta J. Agardh, Sp. Alg., 1848, p. 63; Setchell and 

 Gardner, Alg. N.W. Amer., 1903, p. 253 ; Saunders, Alg. Harriman 

 Exp., 1901, p. 424. Zonaria deusta Agardh, Syn. Alg., 1817, p. 40. 

 Padina deusta Postels and Ruprecht, Illus. Alg., 1840, p. 20. 



The method of reproduction in this species has, apparently, never 

 been observed. It is a plant of the colder waters and has not been 

 collected and studied as much as the other species of the genus. All 

 of the material collected on our coast has been taken in midsummer. 

 In habit and structure, our Alaskan specimens agree with those from 

 northern New England (Phyc. Bor.-Amer., no. 419 and Phyc. Univ., 

 no. 418). 



11. Hapterophycus S. and G. 



Thallus decumbent, dorsiventral, deeply separated into linear lobes 

 radiating from the center, fleshy, short, several times dichotomously 

 branched, concave on the ventral side, convex above, with crenate 

 margins, rounded sinuses and wide, blunt ends ; growth apical ; central 

 part of the frond consisting of large horizontal hyaline, more or 

 less cylindrical cells, from w^hich rows of hyaline cells curve upward 

 and downward terminating in the small surface cells which are filled 



