1925] Setchcll-Gardner : Melanophyceae 493 



terminal and seriate, ellipsoidal; gametangia terminal, with loculi 

 1-2-seriate, 10-14|U, broad. 



Growing on rocks, forming small, irregular, gelatinous or sponge- 

 like cushions, separate at first, but later many coalescing into a common 

 mass. Pacific Grove, California. 



Setchell and Gardner, Phyc. Cont., VII, 1924, p. 12. Hapalo- 

 spongidion gelatiTWsum Saunders, New and little known brown alg., 

 1899, p. 37, pi. 1; Collins, Holden and Setchell, Phyc. Bor.-Amer. 

 (Exsicc), no. 534. 



Microspongium Saundersii differs from M. gelatinosum Reinke 

 in having the erect filaments unbranched, the zoosporangia ( 1) seriate 

 instead of single, the gametangia with loculi 1-2-seriate and inter- 

 calarv instead of lateral and uniseriate, and in details of measurements. 



FAMILY 4. EALFSIACEAE k.jellman 



Thallns crustaceous, flat, discoid and rounded or crenate at the 

 margins, or deeply lobed and dissected, consisting of a flattened mono- 

 stromatic, discoid, basal layer with marginal growth, soon becoming 

 few to many layered by horizontal partitions, with hairs, single, or 

 in small groups, in depressions of the upper surface, with or without 

 rhizoids from the lower surface ; unilocular zoosporangia, either borne 

 at the base of more or less free multicellular paraphyses, collected into 

 more or less distinct patches or "sori" or terminal and forming naked 

 ' ' sori ' ' ; gametangia uniseriate or pluriseriate, terminal or borne on 

 lateral branchlets near the tips of the more or less coalescent vertical 

 rows of the thallus. 



Kjellman, Ilandbok Skand. Ilafsalg., I, 1890, p. 29 (lim. mut.) ; 

 Stragulariaceae Stroemfelt, Om Algenveg. vid Islands Kuster, 1886, 

 p. 49. Lithodermataceae Kjellman, loc. cit., 1890, p. 17. 



The Ralfsiaceae, in the somewhat extended sense in which we con- 

 sider the application of the name, i.e., as including the Lithoderma- 

 taceae of Kjellman, is closely related to the Myrionemataceae (where 

 Reinke places Ralfsia and its segregates) and the Elachisteaceae, with- 

 out being conveniently placed under either. The frond seems clearly 

 a further development of that of the simpler Mtjrionemaspecies, 

 retaining the flattened circular habit as a fundamental type. The 

 coalescence of the vertical filaments, the greater or less separation of 

 fertile areas from sterile, the position of the sporangia and gametangia 

 as to whether terminal or lateral, find close resemblances among the 

 Myrionemataceae or may readily be considered as progressive develop- 



