THE ALGAE OF BERMUDA. 61 



p. 403; Trichosolen antillarum Montagne, I860, p. 171, PI. XI. C. 

 Kemp; Harrington Sound, March, Hervey. 



Yar. filicina var. nov. Frondis circumscriptione late vel anguste 

 lanceolata; axi primario non diviso; axibus secundariis approximatis, 

 aequidistantibus, saepe oppositis, a basi ramulis tenuissimis aequilongis 

 dense obsitis. 



Outline of frond broadly to narrowly lanceolate; main axis not 

 divided; secondary axes closely and uniformly set, often opposite, 

 densely beset from the base with very fane ramuli of equal length. 

 Near Flatts bridge, Feb., Hervey. Type in Collins herb. 



The habit of this variety is strikingly different from that of typical 

 B. Duckassaingii, and the very regular pinnate branching makes it a 

 beautiful object; but in a genus where there is so much variation 

 within each species, it is hardly safe to consider this a distinct species. 



3. B. PENNATA Lamouroux, 1809, p. 133; 1809b, p. 134, PL III, 

 fig. 1 ; Collins, 1909, p. 405; P. B.-A., No. 1871. Rein, as B. plumosa; 

 Kemp, as B. plumosa, in part, B. hypnoides, in part. In Collins, 1909, 

 B. 2>ennata, B. Leprieurii and B. Harveyana were kept distinct, chiefly 

 on the judgment of Miss Vickers, who was familiar with them at 

 Barbados. Since then we have examined some 200 specimens of 

 Bryopsis of Miss Vickers' collecting, and some hundreds of specimens 

 from Bermuda, and we have come to the conclusion that while typical 

 examples of these three are quite distinct, intermediate forms are more 

 common, and specific distinction is impracticable. So far we agree 

 with Borgesen, 1911, p. 145, and 1913, p. 117, but we cannot agree 

 with him in placing them all under B. plumosa (Huds.) Ag. The 

 normal form of B. pennata seems to be a long, simple rachis, with 

 short, distichous ramuli of uniform length, giving a linear outline to 

 the frond. In B. plumosa the rachis bears lateral branches, increasing 

 in length from the apex to the base, so as to give a triangular outline, 

 usually broadly triangular, to the frond. Each of the branches has a 

 similar triangular outline. There is much variation in luxuriance of 

 branching, but in examining a considerable series of B. plumosa from 

 northern Europe and America, to the Mediterranean on one side, to 

 North Carolina on the other, we have seen nothing like the linear form. 

 Among the abundant material from Barbados and Bermuda we have 

 found no plants with repeated triangular outline of the frond and its 

 divisions. We recognize the same varieties as Borgesen, but place 

 them under B. pennata, the oldest name for the distinctly linear forms. 

 The species and its varieties are to be found almost everywhere in the 

 islands, but one must expect more intermediate than typical forms; 

 moreover old plants become denuded, and present many puzzles. 



