116 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.17 



Jania caplllacea Harvey 

 Plate 9, fig. 1 



Harvey, 1853, p. 84; Taylor, 1939, p. 13; Taylor, 1945, p. 195. 

 Jania rubens (L.) Lamx., as interpreted by Dawson, 1944, p. 277, in 

 part. Jania adhaerens Lamx., as interpreted by Setchell & Gardner, 1930, 

 p. 179. 



Thalli minute, growing intermingled with other small algae in tufts 

 or turfs, or over debris, or with sponges, etc., forming colonies of inde- 

 finite extent, sometimes quite dense; branching dichotomous and more 

 or less decussate, commonly with wide angles of 60-90°, not congested 

 above; intergenicula cylindrical, 60-100 /x diam., the ultimate ones 

 usually the most slender, (4) 5-10 (12) diameters long; apices more or 

 less blunt; small accessory attachment discs often found on branches; 

 conceptacles infrequent, the tetrasporangial ones about 300 ju, in dia- 

 meter, terminal, rostrate, bi- or tri-antenniferous. 



Type; Holotype is Tuomey 70, in the Harvey Herbarium, Trinity 

 College, Dublin, Ireland. 



Type locality : Bahia Honda, Florida. 



Mexican distribution: This species is essentially of tropical 

 distribution. The material at hand includes specimens from Clipperton 

 Island, from Guerrero, from the Revillagigedo Archipelago, from the 

 Cape district of Baja California and from several stations in the Gulf 

 of California to as far north as Isia Angel de la Guarda. On the Pacific 

 Coast of Baja California it seems confined to warm bays and lagoons 

 such as Laguna de San Ignacio, Laguna de Ojos Liebre and South Bay, 

 Isla Cedros, avoiding the areas of upwelling. 



The specimen from Isla Guadalupe cited by Setchell and Gardner, 

 1930, as Jania adhaerens Lamx. is this plant. The specimen is variable 

 in diameter, rather large "about 135 fx. broad" in lower parts, but at- 

 tenuated to the more usual diameter for the species above. 



A collection from Puerto Marques, Guerrero (Hubbs 46-239) 

 shows a remarkable method of asexual reproduction. The upper parts 

 of the plants produce triangular propagulae 150-200 fx in diameter with 

 long antenna-like branches from their upper corners. These propagulae, 

 which resemble those of Sphacelaria, were observed to be deciduous at 

 or below the basal point and to form attachment discs from any one of 

 the three limbs in regenerating a new plant. 



