THE ALGAE OF BERMUDA. 129 



2. B. TENELLA (Vahl) J. G. Agardh, 1863, p. 869; P. B.-A., No. 

 L894; Alg. Amcr.-Bor. Exsicc, No. 137, as H. calamistrata; Fucua 

 tenellus Vahl, L802, p. 45. Common on roofs and walls of caves, flat 

 rocks, under mangroves, etc., al all seasons; tetraspores in Now 

 The most common species of the genus; the species of Bostryckia 

 usually grow intermixed with each other, and with Caloglossa and 

 Catenella; it is exceptional to find any one species pure, while the 

 combination of two or more, in varying proportions, is to he found 

 everywhere in the stations noted for this species. B. tenella is quite 

 variable, and the extreme forms seem quite distinct. Forma tenuior 

 J. G. Agardh, L863, p. 869; B. calamistrata Harvey, 1853, p. 56, PI. 

 XIV. C, and forma densa J. G. Agardh, 1863, p. 869; Rhodomela 

 calamistrata Montagne, 1846, p. 36, PI. IV, fig. 1, both occur, often 

 in the same collecting, connected by intermediate forms. 



3. B. sertularia Montagne, 1859, p. 176; P. B.-A., Xo. 2094; 

 Alg. Am.-Bor. Exsicc, Xo. 138. Grotto, Tucker's Town, Dec, 

 Hervey; Gravelly Bay, April, Collins. The tetraspores of this species, 

 of which there seems to have been no record, were found in material 

 from the cave at Gravelly Bay, and are also in material distributed 

 by Farlow, in Alg. Am.-Bor. Exsicc. A stichidium is formed in the 

 limited branch of a main axis, usually occupying only a small part of 

 its length, in the majority of cases below the middle, the unchanged 

 branch extending both above and below T the stichidium, bearing 

 both above and below r ramuli of normal construction; this appears 

 to be an exception to the usual formation in this genus. B. sertularia 

 has been considered by some as a synonym of B. tenella, e. g., De Toni, 

 1903, p. 1162, but the two seem quite distinct. B. tenella is a plant 

 of softer substance, with long monosiphonous ramuli, and Long- 

 lanceolate or linear-lanceolate stichidia; B. sertularia is firmer, only 

 a few of the extreme segments of a ramulus being monosiphonous; 

 the branching is strictly distichous, and the stichidium occupies the 

 middle part of the otherwise unchanged ramulus of the penultimate 

 or ultimate order. 



4. B. Montagnei Harvey, 1853, p. oo, PL XIV. B; P. B.-A., No. 

 1893; Alg. Am.-Bor. Exsicc, No. 136. H. Kennedy, Feb. in Farlow 

 herb.; July, Kemp, as B. scorpioides; Hungry Bay, April, May, 

 Collins; Causeway, Nov., with cystocarps, Hervey. The largest and 

 coarsest species. The cystocarps are large, depressed-globose, and 

 terminal on rather long ultimate ramuli. 



