70 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 26 



Kenyon), D. 2620 (Williams & Kenyon), Laguna de Scammon, 6 m. ; 

 Mason 80 (floating), D. 4045, 8180, 8330, 8613, 8487, Isla Guadalupe 

 (intertidal) ; D. 9-40, Bahia Santa Maria, 35-45 m. (This material tends 

 to be somewhat distichous). Gulf of Calif.— D. 3163, Punta Frailes 

 (drift) ; Revillagigedo Arch. — Howell 360, Bahia Sulphur, Isla Clarion. 

 This tropical species is exceedingly variable in form and habitant, 

 occuring in many kinds of environments from surfy shores to quiet bays 

 and dim sublittoral bottoms. It is an abundant summer annual in the 

 warm bays of Baja California and may be expected along all the warm 

 coasts of Pacific Mexico. It appears in numerous collections from Central 

 America. 



Key to the Mexican Species of Grifnthsia 



1. Branching more or less regularly dichotomous 2 



1. Branching irregular, more or less secund G. tenuis 



2. Cells oval or globular near tips G. ovalis 



2. Cells cylindrical, elongated in upper parts, not globular .... 3 



3. Ultimate cells 70-125 /*, in diameter 4 



3. Ultimate cells 15-30 /x in diameter G. multiramosa 



4. Spermatangia capitate on 1-celled branchlets 



G. anther ice phala 



4. Spermatangia on richly branched small branchlets between the 

 articulations of upper branches G. pacifica 



Griffithsia anthericephala Daws. 



PL 28 

 Dawson 1950a, p. 155, fig. 20-21. 



Thalli 10-20 mm. high, epiphytic, consisting of dichotomously 

 branched uniseriate filaments attached by specialized septate rhizodial 

 branches; cells 150-280 \x in diam. in mid-parts, 4-6 diameters long, 

 decreasing in diameter from upper to lower end and appearing, thus, 

 constricted above the septa; apical cells blunt, reduced in mature 

 plants to 100-70 j± in diam.. without rings of hairs; spermatangia 

 forming dense, ovoid, symmetrical, capitate clusters 80-125 fi in diam., 

 terminating 1-celled branchlets from the cells of the upper parts of 

 the plant, each such vegetative cell bearing 2-3 other cells in addition 

 to the usually solitary spermatangial branch so that the ultimate branch- 

 ing becomes fairly dense, and, in being incurved, somewhat forcipate or 

 dactyloid; tetrasporangia borne in much the same manner as the sper- 

 matangia, on 1-celled pedicels, 2 to several from a cell bearing 2-3 

 vegetative branches, about 70 [x in diam. at maturity, without an 

 involucre; cystocarps scattered, borne on 1-celled lateral branchlets, with 

 a prominant involucre of many incurved, 1-celled branchlets. 



Type: Hubbs 12/7/46, epiphytic on Laurencia, in Herb. A. 

 Hancock Foundation (36924). 



