512 Howe: Phycological studies 



ble and more torulose than is ordinarily the case in the true A. 

 longicmilis {A. Masei) and they are thinner-walled and less monili- 

 form than in A. 7iigricans. The specimen selected for our photo- 

 graph (Pl. 30) represents a common form of the species, though 

 its lobes are narrower, more clavate or subfusiform than those ot 

 the plant originally described and figured by Dickie. 



4. AvRAiNViLLEA LEVIS M. A. Howc, Bull. Torrey Club 32 : 565. 



pl. 2j. f. I ; pl. 26. f. 8-10. 1905 



Avramvillea sordida Murr. & Boodle, Jour. Bot. 27: 70. 1889. 



Not Avrainvillea sordida (Mont.) Crouan ; * Maze & Schramm, 



Essai Alg. Guad. 89. i^yo-'yy. 



Type locality : Cave Cays, Exuma Chain, Bahamas. 



Distribution: Bahamas; Jamaica; Guadeloupe; Grenada 

 {Jide Murray & Boodle). 



Species excludendae 

 After examining authentic specimens, we agree with Murray 8: 

 Boodle t in referring Rhipilia tovientosa Kiitz. to Udotea and in 

 identifying with it Avrainvillea laetevirens Crouan, However, the 

 characters of this species seem to make the line of separation 

 between the genera Avrainvillea and Udotea an almost arbitrary 

 one. Outside of the possession of occasional attachment organs 

 by the filaments — so little abundant that they were overlooked 

 by Kiitzing — the species has more in common with Avrainvillea 

 than with Udotea, bearing, in fact, a close external resemblance to 

 certain conditions of A. longicaulis. Our no. j2og, from North 

 Cat Cay, Bahamas, evidently belongs with Udotea tomentosa. | 



* For a discussion of the technical application of this name, see Bull. Torrey Club 

 32: 566. 1905. 



tJour. Bot. 27: 72. 1889. 



J Udotea tomentosa (Kiitz.) Murray, Jour. Bot. 27 : 239. 1889. 

 Rhipilia tomentosa Kiitz. Tab. Phyc. 8: 12. //. 2S. f. i. 1858. 

 Avrainvillea laetevirens Crouan ; Maze & Schramm, Essai Alg. Guad. 89. 1870-77 



(nomen seminudum). 



Plants 3-6 cm. high, from a scarcely rhizoinatous base, bright-green, fading to 

 yellowish -albescent or isabelline, witliout calcareous incrustation ; stipe subterete or 

 flattened, 0.5-2 cm. long, 2-4 mm. wide, simple : flabellum cuneiform-obovate, obdel- 

 toid, or oblong-cuneiform, 3-5 cm. long, 1-3.5 cm. broad, entire, 2-4-lobed, or at 

 length irregularly lacerate, very obs-curely or not at all zonate, rather thick, uncorticated, 

 spongiose in texture, surface spongiose tomentose, the stipe of similar appearance : fila- 

 ments of flabellum thin- walled, imperfectly reviving on being soaked out, intricately 



