NO. 2 DAWSON : MARINE RED ALGAE OF PACIFIC MEXICO 253 



cortex throughout the thallus just below the surface, 35-40 fi long, 18- 

 20 fx wide, causing some nemathecial modification of the cortex; cysto- 

 carps irregularly scattered through the thallus, embedded, or sometimes 

 appearing to be suspended just inside the cortex; antheridia not seen. 



Type: Holotype not designated and whereabouts of original ma- 

 terial unknown to the writer, though possibly among Wulfen collections 

 in the Natural History Museum, Vienna, Austria. 



Type locality: Adriatic Sea. 



Mexican distribution: Pacific Baja Calif. — D. 5260, 3 miles 

 north of Bahia de Todos Santos, Sept. (drift). Gulf of Calif.— D. 949, 

 Feb., D. 668-40, July, Isla Tiburon; D. 567 (©), Feb., D. 1812 (©), 

 D. 1841-1842 (©), D. 1922 (©), May, D. 10969, 11021 (?), June, 

 D. 3515 (sterile), Nov., Ensenada San Francisco, near Guaymas; D. 

 1716a (0), D. 1722 ($), Ensenada Bocochibampo, near Guaymas, 

 May; D. 1994 (?), Punta Colorado, near Guaymas, May; D. 3481 

 (sterile), Bahia Empalme, Nov.; D. 10939, Punta Prieta, Bahia To- 

 polobampo, June. Sinaloa — D. 3614, Mazatlan, Dec. Nayarit — D. 

 10851, San Bias, June. 



A majority of the Mexican specimens have hollow branches and may 

 be recognized as Grateloupia filicina var. lomentaria Howe. Variability 

 in this feature in some of our collections indicates, however, that it prob- 

 ably has no genetic basis. Several forms occur more or less together in 

 intertidal collections from Ensenada de San Francisco, near Guaymas, 

 Sonora, where the plant is exceedingly common ix\ rock pools during 

 early summer. 



The abundant, slender, multifarious branches and soft, hair-like 

 texture distinguish this plant from other grateloupiae of our coast. 



The material reported by Taylor (1945) as juvenile Grateloupia 

 filicina from Guerrero, Mexico is not this species, but contains fertile 

 tetrasporic plants apparently identical with Grateloupia versicolor J. 

 Ag. from Oaxaca. 



The Baja California specimens referred to this species by Dawson 

 (1945c, p. 60, 66, figs. 10-11) have been reexamined and found by the 

 character of their procarps to belong in the Rhodophyllidaceae, perhaps 

 to Cystoclonium. 



