566 Howe : Phvcological studies 



somewhat moniliform, mostly 6-24 // in diameter ; those of interior 

 often a little larger (reaching 3 5/*), more chlorophyllose and less 

 tortuous : angle of dichotomy commonly acute (about 30°-45°), 

 sometimes obtuse (reaching 120 ). [Plate 23, figure i ; plate 



23, FIGURES 8-IO.] 



In the Bahama Islands, near low-water mark, or when growing 

 under a rock overhang sometimes exposed at low tide : no. 3996, 

 type (Cave Cays, Exuma Chain, 19 February 1905, M.A.H.); no. 

 3574 (Frozen Cay, Berry Islands) ; no. 3966 (Shroud's Cay, 

 Exuma Chain). 



The above-described species, though here appearing under a 

 new specific name attached to a new nomenclatorial type, is doubt- 

 less the same as the species described by Murray and Boodle 

 (Jour. Bot. 27: 70. 1889) under the designation "A. sordida 

 Crn. excl. syn." But according to both the Philadelphia and the 

 Vienna codes of nomenclature, the use of the name Avrainviltea 

 sordida for this species cannot be justified unless perchance it can 

 be shown to be identical with the species described from the 

 Philippines by Montagne in 1844 as Udotea sordida. The combi- 

 nation "A. sordida (Mont.) Crn. mscr." apparently first appeared 

 in print in Maze and Schramm's Essai de Classification des Algues 

 de la Guadeloupe (p. 89. 1870-77) and is there based on quoted 

 synonymy, the citation of Guadeloupe specimens under collection 

 numbers, and the following description : " De couleur brune olivatre 

 a l'etat de vie." Under these circumstances, when one excludes 

 synonymy one excludes all that has technical value in publication, 

 and the name Avrainvillea sordida Crn., if used at all, must be 

 made to apply to Montagne's plant. Our species, if it is to be 

 kept separate from its Eastern Hemisphere analogue, as at present 

 we believe it should, deserves a distinctive name. 



Avrainvillea levis has a smooth compact surface that suggests 

 a 'Udotea at first sight, though its structure is clearly that of an 

 Avrainvillea. The filaments of the flabellum, however, are not so 

 uniform in character as is the case in the other West Indian species 

 of the genus, the filaments of the surface being often more slender, 

 more tortuous, and less chlorophyllose than those of the interior. 



Avrainvillea levis, so far as our experience goes, is the most 

 constant and most easily recognized of the West Indian forms of 

 this puzzling genus. Our remaining specimens, representing at 



