161 



Dictyota spinulosa Harv. 



Nom. Jap,: Hari-amidsu 

 PL. CXXXVII. 



Diclyola spimdosa Harv. in Bccchcys Voy. (Sol.} p. 275; ]. 

 Ag. Sp. I, p. 97; Id. Till Alg. Syst. V, p. 100; Kuetz. Sp. p. 

 556; Id. Tab. Phyc. IX, t. 26, f. II; De Toni Syll. Alg. Ill, p. 

 270; Martens Preus. Exped. p. 130; Heydr. Einige Algen v. d. 

 Loo-choo- oder Riu-Kiu-Inseln p. 102. 



Fronds tufted rising from a scutate disc, 25-30 cm. high, stu- 

 pose at base, broadly linear, 2-3 times pinnately decompound in 

 an alternate manner, spirally torted ; pinnae ovate or ovato-lanceo- 

 late in outline, erecto-patent with round axils ; pinnulae erect or 

 erecto-patent with round axils, roundish obtuse or bifid at apex. 

 Rachis of every segments slightly flexuose. Main segments measure 

 5-10 mm. in breadth, gradually becoming narrower above, lessening 

 to 2-3 mm. in ultimate segments and ciliato-serrated at margin. 

 Surface rarely smooth and free from proliferations, but usually 

 more or less furnished with minute spinose proliferations. In a 

 robust frond proliferations are more numerous and much elongated 

 in short, linear or linear-oblong leaflets densely arising from the 



median portion of segments on both surfaces. Anthcridiai son' 



roundish or ovate, evenly scattered over surfaces without any order. 

 Tetrasporangia more or less densely collected along the median 

 portion of both surfaces of frond. Colour yellowish-brown. Sub- 

 stance rnembranaceous and the plant imperfectly adheres to paper 

 in drying. 



