86 CORALLINACE^. v. 



attenuated upwards, many times dichotomous, the articulations below the fork bifid 

 at the apex, each lobe running out into the commencement of the arms of the forks. 

 Axils wide. Branches divaricate. Articulations cylindrical, smooth, not swollen at 

 the extremities, the nodes very short, indicated by a line only. Colour livid purple, 

 fading to dirty white. 



An exceedingly fragile species, of which it is almost impossible to preserve more 

 than broken fragments. 



2. Amthiroa debilis, Kiitz. ; frond setaceous, dichotomous, fastigiate, very fragile ; 

 branches divaricating ; articulations many times longer than broad, cylindrical, 

 thickened at each extremity ; conceptacles numerous, subsecund. Kiitz. Sp. Alg. 

 p. 700. 



Hab. Florida Keys. Key West, W. H. H. (v. v.) 



Fronds 1 — 2 inches high, as thick as hog's bristle, repeatedly and pretty regu- 

 larly dichotomous, occasionally trichotomous, the articulations below the dichotomy 

 similar to the rest (not bifid or two branched). Branches spreading to all sides. 

 Articxdations generally but one between each furcation, cylindrical, those of the 

 lower and middle regions of the frond incrassated at each end, the upper ones not 

 so. Interstices or nodes simple, scarcely uncovered. Conceptacles numerous on the 

 lower articulations, generally several ranged along one side of the internode. 



A much smaller plant than the preceding, with difitrently shaped articulations. 

 I have not seen anv authentic specimen of Kutzing's plant, which came from Cuba, 

 but my specimens collected within eighty miles of Havana seem sufiiciently to 

 agree with his description. 



3. Amphiroa cretacea, Endl. ; " dichotomous, diffuse, thick, chalky or ash- 

 coloured ; articulations cylindrical, approximate, 1-2 lines long, once and a-half or 

 twice as long as their diameter ; branches distant, flexuous and recurved, cylindri- 

 cal or conical at the apex." Kiitz. Sp. Alg. p. 701. Post, and Eupr. lllustr. p. 20. 

 t, 40, Fig. 104. 



Hab. Unalaschka, Postels and Ruprecht. 



Sub-genus 2. Arthrocaedia. Articulations strongly compressed, frequently 

 winged at the sides, cuneate or obcordate. Conceptacles conical, scattered. 



4. Amphiroa (Arthrocaedia) Californica^ Dne. (?); subdichotomous or irregu- 

 larly branched ; articulations strongly compressed, with a sub-evident midrib, the 

 lowermost cuneate, the upper broadly obcordate with blunt upper angles ; con- 

 ceptacles two to four on each fertile articulation. Dne. CoraU. p. \\2 ? Kiitz. Sp. 

 Alg. 704. A. Hookeri, Harv. in Hook. Herb. 



