166 BOTANICAL MAGAZINE. tVoi. xvil. 



more, especially at the upper portion. Two longitudinal rows of the trans- 

 verse foldings begin to appear along the margins of the lamina. The 

 stipe gains larger diameter and evidently becomes compressed near at the 

 transitional region. But there occurs little addition in the length. The 

 upper portion of the lamina is torn away as the plant grows larger. 



It seems to me that the plants remain in a little advanced stage over 

 the winter. 



As the plant becomes older the lamina enormously broadens without 

 considerable increase in its length. The foldings become remarkable and 

 the upper portion of the lamina splits into several longitudinal segments. 

 In this stage they are hardly distinguishable from a form of Hedoplujllum 

 suhsessile, Setch., at the same time much applicable to the description of 

 Hafgygia Bongardiana f. furcata, Aresch.^^ Sooner or later the both 

 margins of the lamina begin to roll inside at the transitional region, the 

 middle portion of the lamina wearing away till clear to the base. 



The wearing of the lamina extends downward until a narrow portion 

 is left at the transition region which has much increased in its thickness. 

 Hence the plant has now two arms at the top of the short stem, each arm 

 bearing a wide bullated lamina. The external margin of each lamina 

 rolls toward the inner side, and has considerable thickness at the basal 

 region. The cross section at this region, therefore, shows >-shape (fig. 3). 

 The upper portion of the external margin is thin and fimbriated. 



The rolling takes place only at the restricted portion near the base of 

 each arm, and not along the whole part of the external margin. The 

 consequense is a loose spirality. I could not find any plant with the 

 rolling more than 2^ turns (fig. C). 



Not seldom I have met with those specimens which had incomplete 

 rhizoidal processes around the both arms ; and often a plant had one arm 

 with its middle segment torn away to the base, apparently resembling the 

 second order of dichotomy. In the latter case the external segment (the 

 inner portion at the earlier stage) showed no indication of further develop- 

 ment. 



The sori were found in the armed plants. They cover the basal 

 portions of the laminae at the both arms in large patches with irregular 

 outlines (fig. 1). 



The mucilage canals in the adult plants are found, as in the younger 

 ones, in the lamina traversing beneath the both surfaces. The glandular 



1. Obs. Phyc. IV. p.5. 



