100 BOTANICAL JSIAGAZUtE. 



[Vol. XVit, 



The present species has been collected at Wagii, in the province of 

 Shima by the writer ia April, 1902. One of the specimens was provided 

 with sporophyll of Undaria type, at the same time with sori running 

 longitudinally along the both sides of the rachis on the either surface of 

 the lamina. It is not uncommon in Undaria pinnatifida, Sur. to find 

 the longitudinal patches of sori which protruded into lamina from the 

 sporophyll. The sori, however, in my specimen were entirely free from 

 continuation with the sporophyll and were found on about the middle 

 portion of the lamina. The plant suggested new form in the other 

 characters but I hesitated to describe it before I could make more sure of 

 the sori in the lamina. 



A few days ago, scores of the plant have been kindly sent at my 

 request by Messers. H. Nakanishi and D. Yagiu of the Marine Experi- 

 ment Station at Hamajima in the province of Shima. The lot contained 

 various stages of the plant and enabled me to study the exact character of 

 the sori in question. 



While the plant is yet very young, measuring 30-40 cm. in the total 

 length, the lamina is linear-lanceolate, mostly without pinnule. The base 

 of the lamina tapers gently toward the stipe, fading into the margins of 

 the compressed and ancipitate stipe. The dentate ligules at the transition 

 part, which characterise Undaria pinnatifida, were not to be found in 

 our plant, so far as the material concerned. A few of the young plants 

 were furnished with one or two linearly elongated segments at some 

 distance form the transition point. The surface of the lamina is slightly 

 rugose. The plants in this stage are often difficult to distinguish from the 

 sterile form of Alaria. 



A more grown form has the base of the lamina ovate or cordate. 

 The margin of the lamina becomes folded and often pinnated with short 

 blunt segments and broad sinus. The lamina is now bullately rugose 

 especially along the rachis. The sori are already to be found along the 

 both sides of the rachis. They are sharply divided from one another at 

 their terminal portions but soon becoming confluent below, finally fading 

 away before approaching the transition region. 



The full grown plant has the base of the lamina cordate, the margin 

 of the lamina becomes more folded and pinnated. The pinnules are often 

 linearly elongated not seldom with bifid apex and broad round sinus. The 

 pinnation never reaches to tlie rachis but utmost about midway of the 

 lamina. The surface of the lamina becomes extremely rugose, and much 

 more wrinkled transversally along the both sides of the rachis. The sori 



