A NEW JAPANESE ACROSTICHUM. (l50 



and compressed, about 0.3 mm. in diameter; the number of the segments of the 

 incomplete annulus is 12 to 14. The spores are subovoid or subreniform, with 

 a brown irregularly wrinkled exospore. They are 0.05 to 0.06 mm. long and 

 0.035 to 0.04 mm. broad. 



For the reasons stated under Acrostichum YoskinagcB in the last number of 

 this magazine {vide vol. v., p. 1 11.), the present species may be also Included in A. 

 conforme of Swartz. But I have ventured to make it a distinct species, as I did 

 in the case of A. Yoshinagce. This species chiefly differs from A, Yoshlnagcs 

 in the following respects: — The rhizome of the former is elongated, often 1 5 to 20 

 cm. long; while that of the latter is short, at most 4 cm. long according to Mr. 

 Yoshinaga. The sterile frond of the former is oblong-oval, about 0.4 mm, 

 thick, and gradually thin at the margin; while that of the, latter is narrowly 

 lanceolate, about 0.6 mm. thick, and abruptly thin at the margin. The scales 

 on the rhizome and the base of the stipe in the former are lanceolate, linear- 

 lanceolate, or even linear, and attenuated at the apex; while those of the latter 

 are ovate and obtuse at the apex. The veins of the former are more recurved 

 than those of the latter. The vascular bundles of the rhizome of the former form 

 a less complete circle than those of the latter, 



Plate XXIV. Fig. i , whole plant (nat. size); 2, portion of sterile frond ( x 2); 

 3, cross-section of the same ( x 26); 4, 5, branched hairs from the surface of sterile 

 frond -^ X 53); 6, scale from stipe ( x 33); 7, scale from the base of stipe ( X 1 1); 

 8, sporangium (x88); p, spore (X240); 10, transverse section of the basal 

 portion of stipe (x26); 11, transverse section of rhizome (X13); 12, large 

 specimen of sterile frond (nat. size). 



