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jointed, colorless, pointed spines are more or less present. Hair- 

 like roots are emitted from nodes of lower decumbent portion 

 of frond in a transverse row beneath the line of spines. Lower 

 articulations 5-6 times as long as, the upper ones gradually 

 shorter than, the diameter, throughly corticated with a layer of 

 cortical cells which consist of almost rectangular or hexagonal cells 

 arranged in longitudinal rows. Cystocarps unknown to me. Tetra- 

 sporMigia are produced in upper branches (often in proliferous 

 branchlets), mostly along the outer side, sometimes in a transverse 

 row. They are produced from the larger cortical cells which 

 form a ring around the periphery of the nodes, bulging out 

 externally. An examination of the figures 5 and 9 will perhaps 

 serve to make this relation more plain. Colour light red or 

 pinkish. Substance membranaceous and the plant becomes fragile 

 when dried. It adheres imperfectly to paper in drying. 



Hab. On rocks between tide marks : Miyako-jima (War- 

 burg, Heydrich), Kiusiu, Totomi, Saga mi, Boshtl, Iwaki, Wakasa, 

 Sado. 



Hither to-known : In different warmer seas. 



Plate XVII. Fig. 1 : Ceramium clavulatum in natural state 

 and size. ― Fig. 2 : portion of filament, f. — Fig. 3 : terminal 

 portion of nlament, y. — Fig. 4 : cross-section of filament, moder- 

 ately magnified. — Fig. 5 : longitudinal section of nlament, -一; . — 

 Fig. 6 : portion of nlament, showing spines and hair-like roots, 

 — Fig. 7 : portion of filament bearing tetrasporanp-ia, 8 1 °. — 

 Fig. 8 : ramulus forming tetrasporanoia in transverse rows, 12 ま . ― 

 Fig. 9 : portion of a longitudinal section of filament showing the 

 formation of tetrasporangia, つ . 



