﻿PLATE XVII. 

 Ceramium clavulatum Ag. 



CERAMIACE/E. 



Norn. Jap. : Togc-igisn, 



Ccraiuiiau clavulatum Ag. Hauck's Die Meeresalg., p. 113； Bornet 

 Les Alg. d. Schousboe p. 335 ； De Toni Phyc. Jap. Nov. p. 36. ― Ccn- 

 troccras clavulatum Mont., J. Ag. Sp. Alg.， Vol. II， p. 148 ； Id. Epicr., 

 p. 108 ； Harv. Ner. Bor. Amer. tab. 33 C ； Kuetz. Phyc. Gener,， tab. 46， 

 fig. N .—Centroccras cryptacanthiim Kuetz. Sp. Alg. p. 688 ； Id. Tab. Phyc. 

 Vol. XIII， tab. 17. —— Ccntroccras incrnic Kuetz. Sp. Alg., I.e. ； Id. Tab. 

 Phyc, I.e. — Ccntroccras micvacanthum Kuetz. bp. Alg., I.e. ； Id. Tab. Phyc,, 

 I.e., tab. 18. — Ccntroccras leptacanthinn Kuetz. Sp. Alg./ p. 689 ； Id. Tab. 

 Phyc, I.e., tab. 18.- ~ Ccntroccras macracanthum Kuetz. Sp. Alg., I.e. ； Id. 

 fab. Phyc, I.e., tab. 19. — Ccntroccras hyalacantlmni Kuetz. Sp. Alg., I.e. ； 

 Id. Tab. Phyc, I.e. —— し cntroccms oxyacantlnuu Kuetz. Sp. Alg., I.e. ； Id. 

 Tab. Phyc, I.e., tab, 20.— Ccntroccras brachiacanthum Kuetz. Tab. Phyc, 

 I.e., p. 8.， tab. 20. 



Fronds caespitose, often forming a roundish tuft, filiform, 

 2-5 cm. high ； attached to substratum by slender jointed hair-like 

 roots wheih are emitted from nodes of the lower decumbent portion 

 of frond. Filaments usually 177-192 〃- thick, of almost equal 

 thickness throught and almost regularly dichotomous. Branches 

 erect, furnished with proliferous branchlets springing from sides 

 or forks ； when they proliferate from forks, the ramification seems 

 as if tri-polychotomous. Ends of branches are somewhat club- 

 shaped and sometimes straight but usually forked with inrollecl 

 and slightly swollen apices. The cortex surrounding the upper 

 node of every articulation forms a circular ridge or rim, a little 

 prominent oDiiquely outward and upward, so as to make a shallow 

 cup or sheath which seems as if to receive the base of the 

 articulation next, above. Along this rim, a whirl of mostly two- 



