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of simple character stand alternately. The compound nature of 

 fertile pinnae is well shown in tetrasporic pinnae, as the tetra- 

 sporangia are produced from the terminal cells of pinnulae and 

 opposite pinnelke. With respect to the affinity of the present 

 plant we may consider that it exists with Ptiloia Asplenioides, as 

 it is shown by similar arrangement of fructified pinnae, by the 

 alternate disposition of the simple ones, and by the obsoleteness 

 of those of compound nature in both plants in consideration. 

 Of the difference between Ptiloia dentata and PL Asplenioides it 

 is so manifest that we need no further description. Among 

 those Ptilotae which have regularly alternate and similarly con- 

 structed pinnae, such as Ptilota formosissinia, Pt. siliadosa and 

 others (i.e. species of Eaptilota Kuetz), we are far from finding 

 any plant allied to the present Ptilota, In those just mentioned 

 the arrangement of tetrasporangia and tetrasporic pinnae are so 

 widely different from that of those of Ptilota dentata that no one 

 can judge the present plant has any affinity with them. Ptilota 

 Asplenioides has a wide range of distribution in the Arctic Ocean 

 and in the Pacific, alonsf the coasts of America, Kamschatka 

 and Kurile Island, and it reaches clown to Kushiro, a province in 

 the south- eastern coast of the Hokkaido. Ptilota dentala is found 

 in the warmer and southern coast of the Pacific, as far as it is 

 known, extending from Ivvaki to To to mi. In my opinion, it has 

 certainly a close relation to Ptilota Asplenioides having been 

 naturalized and established as a southern representative. This 

 plant is, as it is hitherto-known, only Ptilota which is found in 

 the warmer part of our Pacific coast. 



Plate XVIII. Fig. I : Frond of Ptilota dentala bearing 

 tetrasporangia in natural state and size. ― Fig. 2 : portion of a 



