108 AllT. U. — K. YENDÜ. 



Vesicles are generally' found on tlie basal portions of the 

 ultimate branclilets. Those fully grown are spherical or sub- 

 spherical, round at the apices, with a stalk at the base nearly 

 as long as the diameter of the vesicle. The young ones are often 

 obovate and apiculated. They are provided with few but well 

 defined cryptostomata. 



Recej)tacles are cylindrical, more or less narrowed above, 

 each, excepting the aj^ical ones, borne on the foot of a filiform, 

 subulate bractlet. They are racemosely disposed at the terminal 

 portion of the ultimate branchlets. 



/. valida Yendü. Plate XIA". Fig. 8-12. 



Preiim. List of Fuc. Jup. p. 160. 

 "^^Sargassum validum J. Ag.: Anal. Alg. Coat. III. p. 51). 

 = Sargasswn cxpansum J. Ag.: 1. c. p. 60. 



Remark on the forma. J. Agardh in his paper Anal. Alg. 

 Cont. III. described two new species calling them Sargassum 

 validuvi and S. expansum. These two species are distinguished 

 essentially from each other as well as from Sai'gassuiii confusam 

 by the characters of the rib and the arrangements of the crypto- 

 stomata on tlie upper leaves, and the dentations of the basal 

 leaves. After careful study of the material in our hands I have 

 decided to unite the two species into one and mention it as a 

 forma of the present species. It must be remembered, however, 

 that I have not seen any of the authentic specimens of Agardh's 

 plants and the present disposition is therefore a provisional one. 

 But as far as I could judge from our specimens, provided that 

 I have leferretl them to J. Agardh's species correctly, the specific 

 characters pointed out by that author are by no means constant, 

 and often are reversed. The cryj)tostomata on the leaves of the 

 lateral branches are, as above Jioted, occasionally wanting. The 



