NO. 1 DAWSON! MARINE RED ALGAE OF PACIFIC MEXICO 85 



from the abaxial surface of these very short leaflets) . 



Type: Dawson 626-40, Feb. 15, 1940, in Herb. A. Hancock 

 Foundation (57). 



Type locality: Dredged from a depth of 34-50 m., off Punta 

 Gorda, Baja California del Sur. 



Mexican distribution: Baja Calif, del Sur — D. 7192, Puerto 

 Escondido, 6-10 m.; 6835, 6866, Bahia de San Lucas, 20-37 m. 



Polyneura latissima (Harv.) Kylin 

 PL 40, fig. 2 

 Kylin 1924, p. 37, fig. 27-28; Dawson 1945c, p. 102; Dawson 1949, p. 220; 

 Dawson, Neushul & Wildman 1960, p. 72, pi. 38, fig. 4. Hymenena latissima 

 Harvey 1862, p. 170. 



Thalli 10-15 cm. tall or more, subsessile or shortly stalked, flat, 

 membranous, pinkish to reddish, the young blades oblanceolate, becom- 

 ing somewhat palmately branched or lobed, the older ones more or less 

 deeply incised or lacerated, the segments 2-6 cm. broad; veins conspicu- 

 ous and relatively course, anastomosing to form an areolate reticulum 

 covering all but the blade margins ; tetrasporangial sori minute, scattered 

 over both surfaces of the blade, several in each inter-reticular area 

 between veins; cystocarps numerous, large projecting, irregularly dis- 

 posed over both surfaces; spermatangia forming dull whitish patches 

 over the entire surface which becomes ridged, indented or rugose. 



Type: A collection by Dr. Lyall and C. Wood, in the Harvey 

 Herbarium, Trinity College, Dublin. 



Type locality: Esquimalt Harbor, British Columbia. 



Mexican distribution: Pacific Baja Calif. — Cooper 864, 7 mi. 

 north of Punta Descanso; D. 8038 (Hubbs), Bahia Descanso; D. 136, 

 Rio San Telmo; D. 9648b, outer peninsula, Bahia San Quintin; D. 

 20867 (Neushul) near Punta Cabras; D. 20628, 20804 (Neushul), near 

 Punta Eugenio; D. 9546, 9549 off Punta San Hipolito, 68 m. D. 9552, 

 Isla Guadalupe, 68 m. 



Polyneurella hancockii Dawson var. hancockii 

 PL 40, fig. 3-4 

 Dawson 1944, p. 323, pi. 47, fig. 1-2. 



Thalli 6 to 6.5 cm. high, composed of numerous short-stipitate, 

 entire, ovate-lanceolate, membranous, rose-colored blades 2-3.5 cm. wide, 

 5-6 cm. long when mature, arising from a semi-terete axis several times 

 branched above a small discoid holdfast; blades entire, the margins 

 smooth or with an occasional proliferous bladelet, monostromatic in 

 younger parts, growing by means of an apical cell, without a midrib 

 but with many microscopic veins (some becoming macroscopic in older 

 blades) ; the veins tending to be parallel and to run longitudinally, 

 tetrasporangial sori scattered over blades, more or less regularly spaced, 



