130 THE B OTANICAL MA GAZTNE. t Vo i . xxm. No. 270. 



northern Kurile Islands. As has been pointed out by Setch- 

 ele and Gardner, 1. c., many species and forms described 

 by Ruprecht and Postels under the genus Halossacion or 

 Dumontia seem in large part induced from the polymorphism of 

 this single species due to the age and the habit. The American 

 algologists, however, comprised under the name Halosaccion 

 glandiforme all the saccate species hitherto reported from the 

 north Pacific. But Halosaccion £rmum Rupr. has well marked 

 characters and must be treated as an independent species. I 

 will give some further remarks on it under the separate heading. 



As far as my observation extends Dumontia fucicola P. ct 

 R. and D. decapitata P. et R. are nothing but the young forms 

 of one and the same species, Halosaccion saccatum Kurz. They 

 are abundantly found epiphytic on Rhodomela Larix and on 

 Fucus evanescens on the north-west coast of North America. 

 In the Kuriles as well as in Kamtchatka, the}' are rather rare. 

 The form found on the fronds of Rhodomela Larix is charac- 

 terized by having purplish red, soft texture, and smaller size of 

 frond. The hosts generally inhabit at the high tide marks 

 where the surfs frequent. This naturally checks the growth of 

 the epiphyte, as it must be uprooted or torn away from the 

 base as soon as the size of the frond was large enough as to 

 resist the force of the waves beyond the fastening power of the 

 root. Similar things may be said on D. fucicola on the fronds 

 of Fucus evanescens. The form called D. hydrophora generally 

 grows in a gregareous manner on the rocks between the tidal 

 marks, but not at a projected point, so compactly as to leave 

 no room between the contiguous fronds. The mutual compres- 

 sion, together with the equalness of the height of the fronds, 

 serve to resist the effect of the waves. 



The varieties crassa, coreacea, and Menziesi described by 

 Ruprecht seems nothing but modifications due to the age or 

 habit. 



Ruprecht preferred the name Halosaccion glandiforme to 

 the name H. hydrophora. according to the rule of priority. The 

 minute accounts on doing so is given in Tange p. 280. It is, how- 

 ever, to be stated that Gmelin's definition of Ulva Glandiformis 



