NO. 10 DAWSON : MARINE ALGAE, GULF OF CALIFORNIA 277 



Following the investigations of B0rgesen concerning the history and 

 literature of this species, I am convinced that certain Gulf specimens are 

 to be considered here. The well-developed and ample material at hand 

 corresponds closely with his descriptions and figures of West Indian plants 

 which he designates as var. antillana. Though our material may not be 

 identical with his, I hesitate to add to the literature a different name to 

 designate these plants which seem best identified here. 



D. 395, lower littoral tide pools, Tepoca Bay, Feb.; D. 460, lower 

 littoral pools, San Esteban Island, Feb.; D. 485, Catalina, near Guaymas, 

 ^eb. ; D. 112a, lower littoral. Turner's Island, Jan. 



Genus JANIA Lamouroux 

 Jania rubens Lamour. 



Lamouroux, 1816, p. 212; Harvey, 1846-51, pi. CCLII. 



Although all the Gulf specimens of this genus thus far secured are 

 sterile, the general habit correspondence with Jania rubens is such that it 

 seems tentatively advisable to place our plants under this designation to 

 await further collections and more intensive examinations. 



D. 414, on shore. Pond Island, Feb.; D. & R. 3327, 3237, 3388, 

 Guaymas, Dec. ; D. 700, Turner's Island, July. 



It is interesting to note the occurrence of the genus Jania in the Gulf 

 as well as Amphiroa, neither of which is known to occur on the Pacific 

 California coasts. 



Family Grateloupiaceae 



Genus HALYMENIA (C. Agardh) J. Agardh 



Halymenia actinophysa Howe 



Howe, 1911,p. 509, pi. 34. 



A re-examination of the type specimen of this species was made and a 

 comparison with certain broad membranous specimens from the Gulf. 

 Two collections proved identical in all structural details, as well as in 

 size and external appearance, with Howe's plant from La Paz. Our 

 largest example measures 38 cm. by 29 cm. and is dark rose in color. One 

 smaller specimen shows basal parts : a small discoid holdfast with several 

 broad blades arising from very short (3 mm.) stipes. The blades are plane 

 and broadly elliptical when young, becoming somewhat undulate in age. 



The description and account given by Howe are very ample and need 

 scarcely be elaborated. 



