THE ALGAE OF BEEMUDA. 91 



are subject to much variation with age and environment, and much 

 study of hving plants is needed before we can get a clear idea of specific 

 lines. What we consider as the normal form of the species in Bermuda 

 closely resembles No. 72 of Miss Vickers Algues de la Barbade; in 

 this some apices are acute, some rounded, on the same individual. 

 The branching seems intermediate between D. dichotoma and D. 

 dentata, with a suggestion of lateral branching not found in the former, 

 but not the distinctive character as in the latter. Antheridia were 

 common in material collected at all seasons; tetraspores occurred 

 occasionally on the same individual with antheridia, in July and 

 August. No rhizoidal filaments were seen. Mme. Weber, 1913, 

 p. 182, states that the type of D. Bartayresii cannot be found; she 

 speaks of Harvey's figure as excellent, and we have taken it for our 

 standard. 



6. D. DiVAEiCATA Lamouroux, 1809, p. 331, not of Kiitzing, 1859, 

 p. 10, PI. XXIII, fig. 1; D. acutiloha Kiitzing, 1859, p. 13, PI. XXIX, 

 fig. 1, not of J. Ag. Inlet, Gravelly Bay, Dec, Hervey. Fronds as 

 narrow as in D. linearis, but the dichotomous habit, distinct in young 

 growing branches, is quite obscured in the older parts by the abundant, 

 mostly short, proliferous branches. By these the fronds are often 

 so densely matted that it is not easy to disentangle any individual 

 plant. Antheridia are abundant in this material, but no other form 

 of fruit was observed. The fronds seem to attach themselves by inter- 

 laced proliferous branches, with a few short, monosiphonous rhizoidal 

 filaments close to the tip. 



7. D. ciLiATA J. G. Agardh,i2 ^341^ p 5. Harvey, 1852, p. 110, 

 PI. VIII. A.; B. crenulata P. B.-A., No. 1875, an J. Ag. ?. Rein; 

 Kemp, May, June; South Shore near Paget, Feb., Castle Harbor, 

 Feb., Farlow; Gravelly Bay, Jan., Feb., Harris Bay, Dec, Hervey; 

 Causeway, April, Shelly Bay, May, Hungry Bay, July, CoUins. 

 There is considerable variation in the material which we now include 

 under D. ciliata, but after a re-examinatioii of the form that we dis- 

 tributed as D. crenulata, we do not feel justified in keeping it distinct. 

 It seems to us also that D. crenulata from Barbados, Vickers, No. 75, 



12 The first use of the combination Dictyota ciliata is by Lamouroux, 1809, 

 p. 331, where a synonym is given, Fucus pseudociliatus Lamouroux, 1805, 

 p. 41; a description is given of the latter and figure, PI. XXX, fig. 2; the 

 locality is the Mediterranean. It is now generally acknowledged to be 

 Taonia atomaria (Good. & Woodw.) J. Ag. Being a name proposed for a 

 plant recognized by Lamouroux as already named, Dictyota ciliata Lamouroux 

 never had any standing, and cannot interfere with the subsequent D. ciliata 

 J. Ag. 



