55 



Rhipilia tómentosa Murray & Boodle in Journ. of Bot. XXVII. 1S89. p. 72. 

 Udotea tómentosa Murray in Journal of Botany XXVII. 1889. p. 239. 

 Rlüpilia tómentosa De Toni Syll. Alg. I. 1889 p. 517. 



Udotea tómentosa Howe in Buil. Torrey Bot. Club XXXIV. 1907. p. 512. 

 Udotea tómentosa Collins in Tufts College Studies vol. II. 1909. p. 394. 



Plant varying much in habit, usually solitary, sometimes stout, sometimes thin ; stipitate. 

 Stipes simple, 0.5 — 1.5 cm. long, 0.2 — 0.4 cm. thick, expanding gradually or suddenly into 

 the frond. 



Frond cuneato-flabellate, or rotundato-flabellate, sometimes proliferating after injury, up 

 to 5 cm. in length, sub-ezonate to distinctly zonate; margin entire, fringed, lobed or eroso-lacerate. 



Frond-filaments 30 — 70 p. usually about 50 ( a in diameter, being collapsed and flat in clried 

 specimens; pseudo-lateral branchlets rather short, 50 — 200 p. (usually 100 — 150 a) long, fairly 

 frequent but not abundant, occasionally appearing to be truly lateral. 



Stipes-filaments mostly similar in character and about 45 y. in diameter, but varying up 

 to 70 u. or more, and here and there emitting rhizoids 1 5 [j. in diameter. [Figs. 126 — 129]. 



forma typica, 



Plant stouter, frond cuneato-flabellate, rather thick, sub-ezonate. 



Had. Atlantic. Antilles, Herb. Kütz.\ — Guadeloupe, Gosier, Pointe Laverdure, Mazé n° 233! 

 sub. nom. Avrainvillea laetevirens. 



forma zonata, 



Plant thinner, stipes more slender ; frond rotundato-flabellate or reniform, thin, trans- 

 lucently zonate. 



Had. ATLANTIC. West Indies, St. Jan, off Cant Bay, B'órgesen, n° 1816! about 15 fathoms; also 

 n° 2218! 15 fathoms. 



This species was first described and figured by Kützing (1. c), but, as has been shown 

 in the historical account of the genus, it was afterwards placed by authors in other genera 

 and for some years has been regarded as belonging to Udotea. In the Systematic account 

 p. 53 we give our reasons for reviving the genus Rhipilia, the type of which is Kützing's 

 R. tómentosa. This species has never been recognised in herbaria and, previously to Dr. M. 

 A. Howe's paper in Buil. Torrey Bot. Club (1. c), was never adequately described. The reason 

 for this is probably that the two original plants, well figured by Kützing (1. c.) have been so 

 inaccessible, one (fig. a. of Kützing) having been mislaid in the Kützing herbarium and only 

 lately brought to light by the present owner Madame Weber van Bosse, while the other 

 (fig. a' of Kützing) was preserved in Herb. Sonder at Melbourne, Australia. The first of these 

 plants we have been kindly allowed by Madame Weber to examine ancl on that (our fig. 126) 

 we base the diagnosis given above. Kützing's figure (his fig. a) of the habit is good though 

 it does not exactly represent the outline of the original plant, which is rather stout and stipitate, 

 with a thick flabellate frond obscurely marked with zones. Kützing's figure of the structure is 

 a good enough representation of the loose interweaving of the main filaments of the frond, but 

 though it shows a certain number of T-shaped endings to the branchlets, it does not indicate 



