NO. 10 DAWSON : MARINE ALGAE, GULF OF CALIFORNIA 207 



Valoniopsis Hancockii sp nov. 

 Plate 31, Fig. 9 



Frondes caespitosae supra arenam repentes; filis coenocyticis lis erectis 300-400 

 fi diain. ramellis curtis lateralibusque ad bases septatas abrupte constrictis; apici- 

 bus late rotundatis; membranis translucidis nitentibusque. 



Plants caespitose, creeping, forming small, tangled masses of filaments 

 over loose substrata of sand and small algae, apparently without attach- 

 ment organs when mature ; filaments coenocytic with only occasional cross 

 walls, these mostly at points of branching; prostrate parts very crooked, 

 125-250 fi in diameter; ascending filaments straighter, 300-400 ju, diam., 

 with occasional short lateral branches, these of about the same diameter as 

 the parent filament but sharply constricted at the septate bases; apices 

 broadly rounded; membrane transparent and shiny; chloroplasts dark 

 green, minute, unevenly distributed in dried specimens causing blotched 

 appearance of the filaments. 



Type: Dawson 215, on rocky shore in lower littoral zone, Puerto 

 Refugio, Angel de la Guardia Island, Jan. 27, 1940. Herb. AHF no. 4. 



D. 293 from the same locality is composed mostly of the irregular 

 prostrate, creeping filaments, none of the short, erect parts being 

 branched. These examples are surely the same as D. 215 and undoubtedly 

 represent immature plants. 



Awaiting further collections and observations of this plant in the field, 

 it is here tentatively described as a new species of the hitherto monotypic 

 genus Valoniopsis. The specimens at hand resemble in several ways, but 

 are not the same as, V. pachynema, which occurs with the present species 

 at Puerto Refugio and is conspicuously different in both the fresh and the 

 dried state. It seems to conform to B0rgesen's genus better than to any 

 other. The plants are much more slender and more widely branched with 

 more extensive horizontal parts than V. pachynema. The lateral branches 

 of the erect filaments are sharply constricted at the septum, a character 

 which the other species does not possess. 



Family Gladophoraceae 



Genus GHAETOMORPHA Kiitzing 



Ghaetomorpha antennina (Bory) Kiitz. 



Kutzing, 1849, p. 379; Tab. Phyc. Ill, tab. 60; Setch. & Card., 1920, 

 p. 203; 1924, p. 713. 

 This species, which is found more abundantly along the southern coast 

 of Mexico to Costa Rica and Panama, was collected in the Gulf only in 



