NO. 1 DAWSON: MARINE RED ALGAE OF PACIFIC MEXICO 91 



cuneate in youth, becoming broader in age, 1-2.5 cm. wide, with a pro- 

 minent midrib to 1 mm. wide at the base and with slender, faint, 

 opposite veins; margins smooth, slightly undulate; reproduction not 

 seen. 



Type: E. Y. Dawson 183-40, Jan. 26, 1940, in Herb. A. Han- 

 cock Foundation. 



Type locality: Dredged in 22-44 m., Puerto Refugio, Isla Angel 

 de La Guarda, Gulf of California, Mexico. 



Additional material: Dawson 276-40, Jan. 28, 1940, dredged in 

 12-22 m., Mejia Channel, Puerto Refugio, Isla Angel de la Guarda. 



These two collections appear to represent an undescribed species 

 despite the lack of reproductive characters. The consistently simple, 

 smooth-margined, sharply lanceolate blades (where undamaged) and 

 the branching only from the terete stipe set them apart from the other 

 known species in the key. The plant seems also to be small of stature, 

 but maximum size cannot be judged from the present materials. 



Phycodrys amplissima sp. nov. 

 PI. 44; PL 45, fig. 2-3 

 Thalli 10-13 cm. alt., constantes e laminis una vel aliquot membranaceis late 

 expansis undulatis, e stipite brevi (5-8 mm.) per hapteron discoideum affixo, 

 orientibus; laminae latiores quam altae (ad. 20 cm. lat.) amplae undulataeque 

 asymmetricae late lobatae, nisi ad venas monostromaticae, costam incrassatam 

 necnon venas oppositas ad suboppositas, in partibus inferioribus mediisque 

 prominentes, habentes; venae ad basim plus quam 1 mm. lat., supra gradatim 

 minuentes, nonnullae nervi laterales aeque prominentes ac costae factae, 

 nervos irregulares hie illic plerumque anastomosantes vicissim ferentes; mar- 

 gines laminae ubique minute denticulati; spermatangia maculas rotundatas 

 irregularesve 1-2 mm. diam, in alis inter venas formantia; cystocarpi 600-750 

 ft diam.,rostrati, per laminam totam inter venas sparsi; tetrasporangia non visa. 

 Thalli 10-13 cm. tall, consisting of 1 or a few membranous, broadly 

 expanded, undulate blades from a short (5-8 mm.) stipe attached by a 

 discoid holdfast; blades broader than tall (to 20 cm. broad) ample and 

 undulate, asymmetrical, broadly lobed. monostromatic except at the 

 veins; a thickened midrib and opposite to subopposite nerves prominent 

 in lower and middle parts, these more than 1 mm. wide at their bases, 

 fading gradually above, some of the side nerves becoming as prominent 

 as the midrib and they, in turn, bearing irregular nerves that tend to 

 anastomose here and there; blade margins minutely denticulate through- 

 out; spermatangia forming rounded or irregular patches 1-2 mm. in 

 diam. in alae between veins; cystocarps 600-750 /x in diam., rostrate, 

 scattered over entire blade between the veins; tetrasporangia not seen. 

 Type: Holotype is California Department of Fish and Game, 

 Jan. 26-27, 1960. (E.Y. Dawson 21580) in Herb. Beaudette Foundation. 

 Isotypes are in Herb. A. Hancock Foundation and in Herb. University 

 of California, Berkeley. 



