THE FUCACEvF, OV JA TAX. 97 



portions triquetrous or quadrangulato with jiromincut rid^os, and 

 unexclusively twisted. Tlie stems of the hxteral l)ranchlets are 

 cylindrieal hut in the lower portions slightly angulate. The leaves 

 on the lower portions of the lateral branches are spathulate, 

 sub-obtuse at the apex, attenuated below into a petiole; coarsely 

 serrated on the margin, ribless, with many minute dark spots. 

 Those on the ujiper portions, especially on the fertile branchlets, 

 are much smaller, linear-clavate or often obliquely cuneate and 

 slighth' dentated on the margin, and are extremely soft in texture. 

 It is owing to the latter character that the present is the principal 

 species of Sargassum used as food by the fishermen in certain 

 parts of Japan. 



The vesicles at the base of a lateral branch in young and sterile 

 shoots are ellipsoidal or obovate, measuring 12-1') mm. in length 

 and <S-9mm. in diameter. They are usually slightly compressed 

 with an inconspicuous longitudinal ridge over the apex. The 

 apices of the vesicles are generally round, but often raucronate 

 or even crowned with a small leaflet. The vesicles on the matured 

 fronds are obovate, sometimes pyriform, with a very short stipe, 

 usually round at the apex, but occasionally fusiform and apicul- 

 ated. They rarely exceed 5 mm. in length. 



Receptacles are elongato- conical, shortly pedicelled, each 

 borne on a small, subulate and complanated bractlet, except the 

 terminal one. They are disposed in a raceme on the terminal 

 branchlets. 



Remark on the synonymy. Kützing'^ declared that Sargassum, 

 énerve Ag. and Spongocarpus enervis Kütz. are different plants. 

 But they belong to one and the same species, as J. Agardh"^ had 



1) Phyc. Gen. p. 365. 



2) Spec. Surg. Anstr. p. 01. 



