96 



and I found that the character of muciferous lacunas in root-fibres is im- 

 portant for the distinction of this species from other related species. 

 In a cross-section of thicker root-fibres of typical plants, we find larger 

 and smaller lacunae muciferas (Fig. 11.) Smaller ones are situated im- 

 mediately beneath the cortex, either being scattered or a few being 

 arranged in a row. Besides those smaller ones, larger muciferous 

 lacunas together with some smaller ones are scattered further inward. 

 Even in root-fibres of a very young plant whose stem and lamina are 

 provided with no lacunas muciferas, larger lacunas are present far beneath 

 the cortical layer and outer smaller ones are not yet formed. From this 

 study it appears that the smaller outer lacunas of root-fibres and those 

 of stem and lamina are of later formation than the larger lacunae of 

 root-fibres. 



Plants which very much puzzled me on account of having an aspect 

 very different from that of the typical plants, being entirely destitute of 

 marginal lobes, were brought from the island of Oshima in the province 

 of Idzu. A younger specimen from the same locality was collected by 

 Mr. Shirai and another very young one was collectedat Cape Omaizaki 

 in the province of Totomi by Mr. Fujii (Fig. 12). 



Both Fujii's and Shirai's specimens have a compressed stipe and 

 a greenish-olive lanceolate lamina rising from very obtuse base. Length 

 of stipes are 5 mm and 10 mm, that of laminas 10 cm and perhaps 20 

 cm. (the upper portion being eroded at the distance of 15 cm from 

 the base) with the breadth of 4 and 7.5 cm respectively. In those two 

 young fronds muciferous lacunas are wanting in stipe but are present in 

 root-fibres. The more adult laminas have a length of 40-80 cm with a 

 breadth of 10-15 cm, and their surface is either quite smooth or bullato- 

 rugose. The base of lamina is broadly ovate or somewhat'cuneato-ovate 

 and the stipe is compressed and very short, either being almost sessile or 

 1 — 1.7 cm long. The color of adult plants is exactly similar to that of 

 the typical plant, being dark brown. The margin of lamina is entirely 

 wanting in lobes, but some small lacinias are present in a few specimens. 

 Though the external aspect of plants differs much from typical ones, 

 yet the presence of very small, lacunas beneath the cortex of the stem 

 and the character of root-fibres tell us their nature of the species. I, 

 therefore, placed these plants under a new form with the following 

 diagnosis. 



/. illobata. Lamina lanceolate, smooth or bullato-rugose, destituted in marginal lobes. 



