512 HoweE: PHYCOLOGICAL STUDIES 
ble and more torulose than is ordinarily the case in the true A. 
longicaulis (A. Mazei) and they are thinner-walled and less monili- 
form than in A. xigricans. 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 of 
the plant originally described and figured by Dickie. 
4. AVRAINVILLEA LEvis M. A. Howe, Bull. Torrey Club’32: 565. 
Pay J 85 Pl. 20. J. 8--I0. 1905 
Avrainvillea sordida Murr. & Boodle, Jour. Bot. 27: 70. 1889. 
Not Avrainvillea sordida (Mont.) Crouan ;* Mazé & Schramm, 
Essai Alg. Guad. 89. 1870-’77. 
Type Locatity: Cave Cays, Exuma Chain, Bahamas. 
DistripuTion: Bahamas; Jamaica; Guadeloupe; Grenada 
(fide Murray & Boodle). 
SPECIES EXCLUDENDAE 
After examining authentic specimens, we agree with Murray & 
Boodle ¢ in referring Rhipilia tomentosa 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 Kitzing—the species has more in common with Avrainvillea 
than with Udotea, bearing, in fact, a close external resemblance to 
certain conditions of A. /yngicaulis. Our no. 3209, 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. 
889. 
{ UDOTEA TOMENTOSA t Kiitz.) Murray, Jour. Bot. 27: 239. 1889. 
Rhipilia siaitics Kiitz. Tab. Phyc; 8: 12. pe 2s. f. 7 58 
mea Seine laetevirens Crouan; Mazé & Schramm, Essai Alg. Guad. 89. 1870-7] 
omen seminudum 
Plan $ 3-6 cm. high, from a scarcely thi tous b brigh fadt 
t-green, fading t 
yellowish-albescent or isabelline Cc} » without a leareous in eri seats ‘eg A ag ubterete oF 
egy oO. see . long, 2-4 mm. wide, simple: flabellum cuneiform obovate, obdel- ‘ 
a h sc eiform, re m. long, 1-3.5 cm. broad, entire, 2-4-lobed, OF ® 
ae regularly laceratey very obscurely or not “ all zonate, rather mick, runcorti re 
iose in texture, surface € spongiose-tomentose, th e of similar appe 
suse of flabellaum thin-walled, imperfectly seviting ae ng aket ate inrcately i 
