150 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.3 



medullis plus minusve 6 stratosis, corticibus quibusque plus minusve 8 stratoso, 

 subcorticibus cellulis gradatim magnitudine e cellulis medullibus usque ad cellulas 

 corticales ; tetrasporangiis cystocarpiisque nondum visis. 



Fronds up to 12 cm. high, several from a discoid holdfast, without 

 stolons ; stipes branched, semiterete at first, soon compressed, thick, rigid, 

 expanding gradually into the narrow segments of the blade, these 2-3 

 mm. broad; blades multidichotomous, cuneate in outline, the segments 

 becoming shorter and narrower above, about 450-500 \i thick in the mid- 

 portions, of about 6 layers of medullary cells bordered by about 8 layers 

 of cortical and subcortical cells through which there is a gradual transi- 

 tion in cell size from the smallest to the largest ; tetraspores and cystocarps 

 unknown. 



Type. — Growing on a barnacle, cast up on shore, Laguna Beach, 

 Orange Co., Calif., N. L. Gardner 2562, Feb. 2, 1913; Herb. Univ. 

 Calif. 274046. 



