V. HELMINTHOCLADEiE. 133 



Sub-order 2. Scinaiete. Periphery membranous, very thin, composed of angular 



cellules. 



III. SCINAIA. 



Sub-order 3. Liagoreje. Peripliery formed of moniliform filaments, lying in gela- 

 tine and more or less invested with a deposit of carbonate of lime. 



IV. LlAGORA. 



I. HELMINTIIORA. J.Ag. 



Frond cylindrical, gelatinous, elastic, much branched, \\\i\\ a filamentous axis 

 clothed with a continuous periphery of filaments, invested with a loose jelly ; axis 

 composed of concrete, parallel, longitudinal, articulated filaments of which the 

 interior are of large diameter compared with the exterior; jwiphery of dichotomous 

 moniliform, fastigiate, horizontal filaments emitted laterally by those of the axis. 

 Sporiferous nuclei immersed among the filaments of the peripliery, spherical, com- 

 posed of numerous clavate spore-threads, radiating from a central point. Tetra- 

 spores unknown. 



This genus is proposed by Prof Agardh for the Dudresnaia divaricata of authors 

 whose want of accordance with Dudresnaia and affinity with Nemalion I had already 

 indicated in the Phycologia Britannica. From Nemalion it differs in external 

 habit, but chiefly by the structure of the axis, which is here composed of parallel 

 filaments, concrete together, but not intertwined, and of different diameters, the 

 inner ones being distended, and void of endochrome ; the outer, from which those 

 of the periphery are derived, of much greater tenuity and furnished with colouring 

 matter. 



1 . Helminthora divaricata^ J. Ag.; frond filiform, pale red, very much branched, 

 branches opposite or alternate, horizontal, decompound ; ramuli numerous, divari- 

 cate, scattered, obtuse. /. Ag. Sp. Alg. vol. 2, p. 416. Dudresnaia divaricata^ J. 

 Ag. Alg. Medit. p. 85. Haw. Phyc. Brit. t. 110. Nemalion divaricatum, Kiitz. Sp. 

 Alg. p. 713. 



Hab, Key West, Dr. Blodgett (No. 60). (v. v.) 



Of this plant I have seen but a single American specimen, collected by Dr. 

 Blodgett. It is about three inches long, rather thicker (in the dry state) than hog's 

 bristle, with an undivided stem furnished with several lateral, horizontal branches 



