30 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 17 



Type locality: Epiphytic on Laminaria andersonii. Cypress 

 Point, Monterey County, California. 



Mexican distribution: Pacific Baja Calif. — D. 10427b, on 

 Zostera, Ensenada, Oct.; D. 1126, epiphytic on the sterile basal portion 

 of Gigartina calif ornica, Punta Baja, Apr. ; D. 8360a, on Gigartina, 

 Isla Guadalupe, Dec. ; Howell 626, on CystoseirOj Isla San Martin, 

 Aug. Sinaloa — D. 3624, Mazatlan, Dec. 



Most of the Mexican specimens examined represent rather slender 

 forms of the species, for the most part unbranched in lower parts. 



Kylinia porphyrae (Drew) Papenfuss 



Papenfuss, 1947, p. 438. Chromastrum porphyrae (Drew) Papen- 

 fuss, 1945, p. 325. Rhodochorton porphyrae Drew, 1928, p. 188, pi. 46, 

 figs. 70-75 ; Smith, 1944, p. 179, pi. 49, figs. 8-9. 



Thalli endophytic in the blades of Porphyra perforata, forming 

 reddish patches mostly near the base; endophytic filaments developing 

 from two equal hemispherical cells originating from the germinating 

 spore, branching irregularly, pinnately, mostly at nearly right angles and 

 spreading through the superficial matrix above and below the host cells 

 or sometimes between them, also giving rise to erect branches of 1-2 or 

 more cells, these sometimes projecting beyond the surface of the host 

 and becoming free ; free branches sometimes in turn bearing short branch- 

 lets; cells of endophytic filaments mostly wider in the middle than at 

 either end, to 10 ju, in diameter, with a stellate chromatophore and a 

 large central pyrenoid ; cells of free filaments cylindrical, 5-8 fi in dia- 

 meter; reproduction by monosporangia borne both terminally and lateral- 

 ly on the free filaments and their branchlets. 



Type: Holotype is Gardner 3276 on sheet 294552 in the Her- 

 barium of the University of California, Berkeley. 



Type locality: Lands End, San Francisco, California. 



Mexican distribution: Pacific Baja Calif. — D. 9641a, in Por- 

 phyra perforata on rocky shore 1 mile inside Bahia San Quintin from 

 end of peninsula, Apr. 



In the Mexican material the growth of the endophyte is luxuriant 

 within the matrix of the host on either side of the cells, but the vertical 

 filaments of 1-2 cells scarcely project beyond the surface. Production of 

 sporangia was not observed with certainty. 



