NO. 1 DAWSON : MARINE RED ALGAE OF PACIFIC MEXICO 11 



Type: Holotype not designated, but represented by Carmichael's 

 material, collected in about 1820, in the Hooker Herbarium at Kew, 

 England. A fragment is on slide 1510 in HAHF. 



Type locality: Epiphytic on Zostera, Appin, Argyllshire, Scot- 

 land. 



Mexican distribution: Pacific Baja Calif. — D. 1255, on Gas- 

 troclonium coulterij Punta Baja, Apr.; D. 10560a, on Gelidium micro- 

 physa, Punta Norte, Isla Cedros, Oct. 



This species differs by its monostromatic basal disc from other species, 

 such as Erythrotrichia calif ornica and E. tetraseriata, which exhibit 

 quite similar erect thallus parts. 



It should be pointed out that an error exists in the measurements 

 given by Batters for the breadth of the erect filaments. Examination of 

 the type material indicates that his figures "10-200 /a" should read 

 "10-20 /t." 



Erythrotrichia pulvinata Gardner 

 Plate 1, fig. 7 



Gardner, 1927, p. 238, pi. 24, figs. 1-3; Smith, 1944, p. 164, pi. 36, 

 fig. 3; Doty, 1947, p. 159; Hollenberg, 1948, p. 156; Dawson, 1949, p. 

 222, 227. 



Thalli epiphytic, usually on the utricles of Codium fragilcj consisting 

 of a pulvinate base 50-250 ^ in diameter from which numerous erect 

 fronds arise; erect fronds 1.5-3 mm. long, at first uniseriate, of quadrate 

 cells tending to be shorter than broad, above divided by longitudinal 

 walls in one plane to form a unistratose, ligulate blade to 8 cells wide 

 (70 jLt), the cells in rather regular horizontal and vertical rows; repro- 

 duction by spherical monosporangia cut off from cells in the flattened 

 upper thallus parts, becoming 12 /a in diameter before release. 



Type : Holotype not designated, but represented by Gardner 2896, 

 May, in the Herbarium of the University of California, Berkeley. 



Type locality: Epiphytic on the utricle-tips of Codium fragile. 

 Pebble Beach, Carmel Bay, California. 



Mexican distribution: Pacific Baja Calif. — D. 1274a, Punta 

 Baja, Apr.; D. 1411, 1409a, Punta Santa Rosalia (fertile) Apr.; D. 

 10512, Punta Norte, Isla Cedros, Oct.; D. 9080, Islas San Benito, 

 Apr.; Howell 20a, Bahia San Bartolome, Aug.; D. 9140, Bahia Asun- 

 cion, Apr. ; D. 9508, Punta Abreojos, Apr. 



