386 University of California Puhlications in Botany [Vol. 6 



Pelvetia fastigiata f. gracilis Setchell et Gardner forma nov. 



Profuse dichotomo-raniosa J ramis eentralibus longioribus, externis 

 curtioribus, plantam totam plus minusve sphericam efficientibus ; 

 ramellis curtis densisque ad basem frequenter orientibus ; f rondibus 

 gracilibus, ramis terminalibus 1-3 mm. diam. 



Plants profusely dichotomously branched, central branches becom- 

 ing much longer than those on the outside of the mass, giving to the 

 whole plant a more or less spherical outline ; frequently branches arise 

 from near the base and develop a mass of short branchlets ; fronds 

 slender, the terminal branchlets 1-3 mm. diam. ; fruiting in the sum- 

 mer and autumn. 



Growing in the middle of the littoral belt. Carmel Bay, Pacific 

 Grove and Santa Catalina Island, California. In these localities 

 plants grow in groups quite separate from the typical P. fastigiata. 

 The type locality is Carmel Bay, California. 



This form, though morphologically connected with the species by 

 plants intermediate in size, seems to be sufficiently distinct to warrant 

 a form name on account of its profuse and delicate branches, and 

 different fruiting season. Plants of forma gracilis begin fruiting 

 early in the summer and reach their climax in the late fall, whereas 

 those of P. fastigiata reach their maturity two or three months later. 



Sargassum dissectifolium Setchell et Gardner sp. nov. 



Sargassum piluliferiim (Turn.) Ag., Farlow, Anderson and Eaton, 

 Alg. Exsicc. Amer.-I3or., no. 102; Collins, Holden and Setchell, Phyc. 

 Bor.-Am. (Exsicc), no. 537a, not &. Not C. Ag., Sp. Alg., 1823, p. 

 27. Not Yendo, Fucaceae Japan, 1907, p. 54. Not Fucus pilulifer 

 Turn., Hist. Fus., vol. I, 1808, p. 145, pi. 65. 



Perenne, dioicum ; radice solicla, rugosa, plus minusve discoidea ; 

 stipite tereti, usque ad 18 cm. longa, apice 2-5 ramos teretes alter- 

 nosque post fructificationem dissolutos ferentibus : ramis primariis 

 ramellos steriles (folia), alternos, frequenter dense congestos, den- 

 droide et dichotomo in 15-25 segmentis parce complanatis, 2-3 cm. 

 longis, eostatis, dissectos, gerentibus ; ramis vetustis oribus projectis 

 curtis spinosis plus minusve ramosis indutis ; ramis secondariis 

 numerosis ex axillis superne curtioribus, inferne longioribus ori- 

 entibus, folia depauperata eorum frondium principalium similia 

 gerentibus vesiculas et receptacula in axillis producentibus ; vesiculis 

 vulgo solitariis, levibus sphaericis, 3.5-6 mm. diam., in apicibus 

 pedicellorum diametron vesiculorum aequantorum; receptaculis in 

 axillis segmentorum stirilium dense dendroide congestis, multo vesi- 

 cula aut folio depauperato ornatis; frondibus fructiferis saepe nudis, 

 foliis dlsintegrantibus ; conceptaculis conspicuis; cryptostomatibus 

 numerosis. 



Frond arising from a solid, rugose, more or less disk-shaped hold- 

 fast, 4.5-7 dm. high ; stipe terete, up to 18 cm. long, bearing 2-5 

 terete, alternate branches at its summit, distintegrating after fruiting ; 



