1/j2 AET. 12. — Tv. YEXDO. 



root. The result is an irregularly knotty mass as shown in 

 PI. XVII, fig. 6. 



The stems of the shoots or the branches are triangular with 

 sharp edges, with strongly retrofractive leaves spirally disposed. 

 The leaves on the basal portions are lanceolate or spathulate, 

 anci pitons or immersedly costated, and entire or sparingly 

 dentated on the margins. Those on the upper portions are linear 

 clavate, 2-4 mm. wide and 2-5 cm. long ; in the typical plants 

 the margins are entire but often coarsely denticulated. In 

 substance the leaves on all parts are thick and coreaceous. 

 Cryptostomata are entirely wanting. 



Not infrequently the stems are loosely twisted and arched in 

 the upper portions and send out the leaves in a secund manner 

 towards the convex side (fig. 10). 



Vesicles are elliptical, measuring 4-5 mm. in diameter and 

 5-7 mm. in length. When fully grown they are mucronated or 

 aristated at the top, and have a short ancipitous stipe at the 

 base. They are found solitary near the base of a lateral branch 

 or branchlet. 



Keceptacles unknown. 



Remark on the systematic position. As our plant has not 

 been found in fructification, the exact systematic position is 

 uncertain. The present disposition is therefore a provisional 

 one. It may be considered to have some resemblance to Sargassum 

 virgatwih Ag. or Sargassum concimim Grev., but the augulate 

 stems and the non-glandulated leaves do not accord with the 

 description of either species. 



Localities. Sagami Prov. ( !) ; Shima Prov. (!) ; Hiuga 

 Prov. (!) ; 



