y. CRYPTONEMIACE.E. I69 



Hab. On the Pacific Coast of the Mexican Republic, Liebman ! (v. s. in Herb. 

 T. C. D.) 



Closely related to the preceding species, but more robust (half a line in diameter), 

 and softer when moistened, soon decomposing if kept in fresh water. 



3. Ahnfeltia ? jnnnidata ; frond rigid, terete, irregularly branched ; branches 

 few, elongate, subsimple, compressed above, and more or less closely pinnulated 

 with setaceous, short ramuli. 



Hab. At Key West, rare, W. H. H. (42.) (v. v.) 



Frond twice as thick as a hog's bristle, 4 — 5 inches long, terete below, sub- 

 compressed above, very in'egularly branched, and chiefly from the lower part. 

 Branches long, arched or straight, sub-siinple, either quite naked or set at distances 

 of a line or two apart with setaceous, horizontally patent ramuli. These are two 

 to four lines long, alternate or opposite, sometimes fasciculate or imperfectly whorled, 

 but mostly distichous, as thick as a hog's bristle, distant or crowded. Colour a dull, 

 blackish purple. Substance rigid and wiry, as in A. plicata. The structure of the 

 medullary stratum is very compact and dense, and nearly as in A. plicata ; but the 

 cortical stratum is very narrow, composed of very minute cells, in few rows. 



I found but two specimens of this plant at Key West. It seems to me to be a 

 well-marked species, and related to the plants of this genus, if not a genuine con- 

 gener ; a fact which cannot be ascertained without more complete data. 



V. CYSTOCLOXIUM. Kiitz. 



Frond carnoso-membranaceous, terete, decompoundly branched, composed of 

 three strata of cells ; medullary stratum cord-like, formed of elongated, longitudinal, 

 interwoven confervoid filaments, anastomosing and dichotomous, their branches 

 arching outwards among the large rounded cells of the intermediate stratum ; cells 

 of the cortical stratum small, roundish-angular. Conceptacks half immersed in the 

 branches, containing within a thick closed pericarp (formed from the cortical layer) 

 a compound nucleus, consisting of several nucleoli or masses of minute spores, 

 separated by sterile filaments. Tetraspores dispersed through the cortical layer of 

 the branches, zonate. 



This genus, as originally proposed and admirably illustrated by KUtzing, in his 

 Phycologia Generalis (p. 404, t. 58, fig. I.) is readily distinguished from all neigh- 



VOL. IV.— ART. 5. z 



