510 Howe : Phycological studies 



Fusco-nigiescent or sometimes sordid- or tawny-green when 

 living, of a similar color on drying, gregarious or scattered, with 

 or without a horizontal rhizome : stipe flattened or subterete, i — 15 

 cm. long, 3-10 mm. wide, rarely deficient, simple or forking near 

 the base : flabellum cuneate obovate, oblong, or sometimes sub- 

 orbicular, now and then diffuse, imperfectly complanate, and 

 irregularly lobed, i — 12 cm. broad, coriaceous in the smaller 

 forms, thinner and of looser texture in the larger, most obscurely 

 or not at all zonate, the surface strigose, subvelutinous, or minutely 

 spongiose : filaments of flabellum cylindrical, strongly constricted 

 just above the dichotomy, rarely here and there subtorulose, 

 usually firm-walled and mostly rather straight and rigid, 28-70 /i 

 in diameter ; filaments of surface of stipe commonly more slender, 

 interwoven, rhizoid-like, those of interior sometimes crowded with 

 amylum grains. 



Type locality : " Ad Antillas " [Antigua] ; type specimen 

 in the Sonder collection of the National Herbarium of Victoria, 

 Australia. 



Distribution : Bermuda and the West Indies. 



The maintenance of the binomial Avrainvillea longicaiilis for 

 the present species and the crediting of the name to Murray & 

 Boodle are both, we believe, technically correct, even though it 

 may prove a source of some confusion for a time, inasmuch as 

 Murray & Boodle evidently intended that another species — the 

 true A. 7iigricans Decaisne — should bear Kiitzing's name longi- 

 caiilis. But, as Murray & Boodle in proposing the new combi- 

 nation Avrainvillea luns^icauHs cited Kiitzing's Rhipilia longicaiilis, 

 it cannot be denied that this new combination applies also to 

 Kiitzing's species and that it applies to it in a peculiar and typical 

 way. Notes by the present writer on Kiitzing's type-specimen 

 have been published in the place cited above and in the same 

 paper also (pages 567, 568) are comments on the relationship of 

 the present species to A. nigricans. A. longicaulis 2ind A. nigricans 

 often grow intermingled and resembling each other so closely that 

 they cannot be determined without a microscopical examination, 

 yet the more that we see of them the more we are inclined to the 

 belief that they represent true species. 



3. Avrainvillea Rawsoni (Dickie) 

 Rhipilia Raivsoni Dickie, Jour. Linn. Soc. 14: \^\. pi. 11. f. i, 

 2. 1874. 



