246 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 3 



though occasional spiny oogonial ones may occur. In general, the oogonial 

 receptacles are shorter and more robust than the antheridial ; yet in some 

 cases almost the opposite was found to be true. All the specimens here re- 

 ferred to S. sinicola are fundamentally indistinguishable in general ap- 

 pearance and morphology. The leaves, variable in size, are basically the 

 same in shape, dentation, and cryptostomata. The vesicles are nearly 

 always spherical and rather large, a form peculiar to this group (see pis. 

 38 and 39). 



In this complex, variation in the inflorescences seems generally to up- 

 hold the observations mentioned above, that oogonial inflorescences show 

 closer association with modified vesicles and antheridial with leaves. How- 

 ever, here again, definite exceptions have been observed in some plants. 



As evidenced by specimens collected and observed cast up on the beach 

 at Kino in July (see below), the floating habit has considerable influence 

 on the gross morphological appearance of plants. A prolonged life in the 

 floating condition may account for the undulate, crisped leaves and for 

 modification of receptacular parts. It is undoubtedly the cause of the 

 lighter, yellowish color of these specimens. 



Apparently, differences in the age of plants or the luxuriance of 

 growth also determines to some degree the extent of branching of the re- 

 ceptacles. The name Sargassum cylindrocarpum S. & G. was given to one 

 bearing much-branched, only slightly spiny receptacles. S. sinicola was 

 first used to apply to a form with less abundantly branched, smooth recep- 

 tacles. In no particular does it seem possible with the knowledge at hand 

 to distinguish the type specimen of the latter from that of S. polyacan- 

 thum f. americanum S. & G. 



Sargassum paniculatum (det. W. A. Farlow) appears on the label of 

 a specimen from Guadalupe Island outside of the Gulf. This plant has 

 been referred to S. calif ornicum (Grun.) Setchell. The leaves are shorter 

 but of the same proportions in this example, and the antheridial recep- 

 tacles are very slender, but again its basic nature and aspect do not suggest 

 its distinctness from certain plants referred here to S. sinicola. 



The collections made in the summer of 1940 between Kino and Tur- 

 ner's Island include both Sargassum sinicola (in the broader sense) and a 

 species which is here named Sargassum Camouii after the French-Mexi- 

 can fisherman who guided and navigated us to the island. On the beach 

 at Kino, both were cast up and could easily be distinguished by their con- 

 trasting color, S. sinicola a light, shiny yellow brown, S. Camouii a dull 

 gray brown. On the south shore of Tiburon Island, S. Camouii was found 

 growing, attached by woody, basal disk or cone holdfasts to the cobble- 



