154 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 17 



Silva 4789, Islas Todos Santos; D. 32, Cabo Colnett, Jan.; D. 8690, 

 Punta Baja, Jan.; Howell 56a, Isla San Martin (dredged) ; D. 9112b, 

 Islas San Benito, Apr.; D. 9861, South Bay, Isla Cedros, Apr. 



Most of the specimens of this plant from infratidal stations are 

 markedly divaricate, slender, and show a modification toward loss of the 

 acute wings and narrowing, thickening and elongation of the inter- 

 genicula. In extreme specimens there is a complete loss of the acute, up- 

 swept wings, the intergenicula remaining subcylindrical or compressed 

 and not much broader at the top than at the bottom. Such examples have 

 been dredged from depths as great as 50 meters. 



Bossea gardneri Manza 



Manza 1937a, p. 563; Manza 1940, p. 306, pi. 15; Smith, 1944, p. 

 235, pi. 52, fig. 2; Doty, 1947, p. 169; Dawson 1949, p. 220, 222. 



Thalli saxicolous, to 10 cm. high, consisting of a few much-branched 

 erect parts from a crustose basal stratum ; erect parts dichotomously 

 branched in one plane, the branching at variable angles in different 

 plants but tending usually to be fastigiate rather than divaricate, with- 

 out pinnate branches, or commonly with pinnate branches rare above and 

 occasional below, and (or) with proliferous branches from faces of inter- 

 genicula; segments compressed to subcylindrical at the very base, but 

 otherwise strongly compressed or flattened throughout; branch tips fre- 

 quently somewhat attenuated ; intergenicula broader than long, 2.5-3.5 

 (to 4.0) mm. broad, prominently winged by a broadly rounded lobe on 

 either side of a prominent, thickened midrib, these wings of successive 

 intergenicula separated only by very narrow or short angles so that 

 branch-margins appear indented but not serrate ; intergenicular medulla 

 multizonal, of straight filaments; genicula unizonal, about 200 jx long; 

 tetrasporangial conceptacles domoid, 500-750 /x in diameter, (1) 2-4 (5) 

 on the segment-faces, usually on the wings ; tetrasporangia zonate, ob- 

 long, 130-175 IX. long; antheridial conceptacles low-conical, more or less 

 rostrate, 600-750 /a in diameter, 3-8 on a segment face, irregularly 

 arranged. 



Type: Holotype is a collection by Gardner, Dec. 1909, on sheet 

 545763 in the Herbarium of the University of California, Berkeley. An 

 isotype is in HAHF. 



Type locality: Pacific Grove, Monterey County, California. 



Mexican distribution: Pacific Baja Calif. — D. 212, 8 km. 

 south of Punta Descanso, Jan.; D. 10282, mouth of Rio San Miguel, 



