Howe: Phycoi.ogical studies 509 



Avrainvillca longicaulis Murr. & Boodle, />. />. Jour. liot. 27 : 70. 

 //. 228. f. i-j. 1889. (Excluding syn. Rhipilia lougicaulis 

 Kiitz.) 



Usually fusco-nigrescent when living or rarely tawny-green, of 

 a similar color on drying or somewhat darker or more sordid, gre- 

 garious or scattered, normally with a stout horizontal rhizome 

 (commonly left in substratum as ordinarily collected), or, when 

 small and poorly developed, with a somewhat bulbous or difform 

 base : stipe cylindrical or flattened, 1-16 cm. long, 3- 1 4 mm. wide, 

 now and then deficient or scarcely differentiated, simple or rarely 

 forked near the base : flabellum varying from suborbicular (reni- 

 form-cordate when young) to cuneiform (sometimes subclavate 

 when young), 1—25 cm. broad, entire or more or less lacerately or 

 digitately lobed, thin and membranous in the broader forms, 

 thicker and more coriaceous in the narrower, felt-like in texture, 

 very obscurely or not at all zonate, the surface subvelutinous or 

 minutely spongiose : filaments of flabellum distinctly moniliform 

 or torulose (at least those near the surface) usually firm-walled 

 and rather straight and rigid, 33-70/^ in maximum diameter, fila- 

 ments of stipe similar, but with more differentiation between those 

 of surface and those of interior : sporangia mostly subpyriform, 

 varying from clavate to subglobose, 0.35-0.83 mm. x 0.20-0.35 

 mm., usually exserted once or twice their own length ; spores 

 ovoid, pyriform, or elongate-ellipsoidal, 1 30-300 /^ X 66-120/i. 



Type locality : lies des Saintes, near Guadeloupe, West 

 Indies; type specimen in the herbarium of the Museum d'Histoire 

 Naturelle in Paris. 



Distribution : Bermuda, southern Florida, the West Indies, 

 and South America. 



Avvainvillea nigricans, as here conceived, is widely variable in 

 form and size, though tolerably uniform in the character of its fila- 

 ments. Further remarks by the writer on its range of variation 

 may be found in the place cited above. 

 2. AvRAiNViLLEA LONGiCAULis (Kiitz.) Murr. & Boodle,/./. Jour. 



Bot. 27 : 70. 1889. (Excluding all hut syn. Rhipilia longi- 



caiilis Kiitz., which may be fairly considered the "type" of 



the new binomial.) 

 Rhipilia longicaidis Kiitz.* Tab. Phyc. 8: 13. //. 28. f. II. 



1858. 

 Avrainvillca Mazei Murr. & Boodle, /. c. pi. 288. f. 6. 



*M. A. Howe, Bull. Torrey Club 32 : 586. 1905. 



