Dumontia filiformis (Fl. Dan.) Grev. 



Norn. Jap. ； Rminon-sd. 



PL, XVI， Figs. 1-8. 



Dumoutia filiformis ( FL /入？〃.) Grcv, AIg\ Brit. p. 165, tab. 

 XVII； Harv. Phyc. Brit. tab. LIX ； Kuetz. Sp. AI-. p. 718 ； Id. 

 Phyc. Gen. p. 394, t. 74, f. 2 ； Id. Tab. Phyc. XVI， t. 81 ； J. Ag. Sp. 

 Alo'. II, p. 349 ； Id. Epicr. p. 275 ； id. Florid . Morphol. t. 17, f. 15 ； 

 Hauck Meeresalor. p. 129, f. 50 ； De Toni Syll. Alg. IV， p. 1621; 

 岡 村， 日本— i 蓬 観名歲 P- 9-- ― Conferva fi I if or mis FL Dcm, L 14.S0, fig. 2. 

 — Dumoutia contort a Rupr. Tange des Ochot. Meer., p. 295. — uastri- 

 diuin fihjomc Lyngb. Hydr. Dan. p. 68, tab. i 7. 



Jriab. : Urupp Island. Cystocarps and tetraspores : July-Aup*. 



Formation of the cystocarpf. Among the materials collected at 

 Urupp Island by several persons I found a few dried specimens of the 

 plant, and fortunately .enough I was able to study the formation of 

 the cystocarp in them. 



The carpoeonial branch, mostly consisting of =5 cells, arises as a 

 short lateral branch of a lontntuclinal filament which forms the inner 

 layer of cortical stratum and gives rise to forked moniliforni filaments. 

 It is strongly curved toward its free extremity as it is represented in 

 Schmitz's Befruchtuncr der Floricleen Taf. V， fip*. 22, and the terminat- 

 ing cell, the carpoo-onium, carries a lono- twisted trichopyne. Auxiliary 

 cell-branches consist of more or less curved rows of mostly four some- 

 times five disk-shaped cells which are easily distinguished from the 

 remaining ones by thir enriched contents. They are pretty abun- 

 dantly prepared in the vicinity of the procarp as short branches in a 

 position similar to that where it takes its ori^n, and also are often 



