CODIACEAE. 611 



dichotomy or pseudo-dichotomy, or sometimes apparently terminal, the filament 

 continued by a lateral innovation; zoospores numerous (about 200-500 to a 

 sporangium), ellipsoid or ovoid, 20 40 /* X 20-25^. 



Green Cay, W. C. Cokcr, June 30. 1903, dredged in 4 fathoms, a small amount 

 of material preserved in formalin. There is a possibility that the plant belongs in 

 Cladophoropsis, but the terminal rather than intercalary sporangia and the large 

 zoospores, on some of which indications of a circle of cilia have been noted, have 

 suggested its reference to Bryobe&ia, the .Tavan type-species of which it resembles 

 closely, though the Bahamian plant is evidently longer and coarser, with filaments 

 twice as broad. 



Family 12. CODIACEAE. 



1. AVUAINVILLEA Decaisne, Ann. Sci. Nat. Bot. II. 18: 108. 1842. 



IkADELiA Chauv. Eecherches 124. 1842. 

 Chloroplegma Zanard. Mem. R. 1st. Yen. 7: 290. 1S3S. 



Thallus eventually developing a flabellum (usually stipitate). 



Fusco-nigrescent, yellowish brown, or tawny green ; surface subvelutinous, 

 spongiose, or strigose ; filaments of flabellum 2870 u 

 in diameter. 

 Filaments of flabellum moniliform. 1. A. nigricans. 



Filaments of flabellum cylindric, with a strong constric- 

 tion at base of each branch, rarely subtorulose. 2. A. longicanlis. 

 Olivaceous or cinereous ; surface smooth and compact ; fila- 

 ments of surface of flabellum 6-24 fi in diameter. 3. A. levis. 

 Thallus not developing a 'flabellum, forming more or less digi- 

 tate, sometimes capitate lobes, these commonly very irregular 

 in form, and often branching, diffluent, or anastomosing. 4. A. Raicsoni. 



1. Avrainvillea nigricans Decaisne, loc. cit. 



Fradelia fuliginosa Chauv. Eecherches 124. 1842. 



Avrainvillea longicaulis Murr. & Boodle, Jour. Bot. 27: 70 p.p. /)/. 228. 

 f. 1-5. 1889. [Excluding syn. Iihipilia longicanlis Kiitz.] 



Common in shallow water, mostly on reefs or in places protected by reefs. 

 New Providence, Andros, Berry Islands, Great Bahama, Gun Cay, Elenthera, Exuma 

 Chain, Mariguana, Caicos Islands, Castle Island, and Great Ragged Island : Ber- 

 muda and Florida to South America. Type from lies des Saintes, near Guadeloupe. 



Forma fi'tlva M. A. Howe (in C. II. & S. Phyc. Bor.-Am. 1!,&0) differs from the 

 tynical form in its thicker, more snon^iose. and usually more cuneate flabellum, in 

 its flatter, broader, less differentiated stipe, and in the firmer-walled, usually 

 coarser, though often more tapering filaments, which are less regularly moniliform, 

 often more tortuous or zig-zag, more frequently and more divaricately dichotomous, 

 and nearly always yellow or yellowish brown rather than fuscous at maturity. 



2. Avrainvillea longicaulis (Kiitz.) Murr. & Boodle, Jour. Bot. 27: 70 p.p. 



188&. [Excluding all but syn. Bhipilia longicanlis Kiitz.] 



IHiipiUa longicaulis Kiitz. Tab. Phyc. 8: 13. pi. 28. f. II. 1S58. 

 Avrainvillea Mazei Murr. & Boodle, loc. cit. 



Common in shallow or moderately deep water, often with .4. nigricans. New 

 l'rovidi'ncc, F.xuma Chain, YVatling's Island, Mariguana. Caicos Islands. Castle 

 Island, Great Ragged Island, and Salt Cay : Bermuda to Barbados. Type from 

 Antigua. 



3. Avrainvillea levis M. A. Howe, Bull. Torrcv Club 32: 566. pi. S3, f. 1; 



pi. 26. f. 8-10. 1905. 



Avrainvillea sordida Murr. & Boodle, Jour. Bot. 27: 70. 1889. Not A. 

 sordida (Mont.) Crouan ; Maze & Schramm, Alg. Quad. 89. 1870-'77. 

 [Based upon Udotea sordida Mont, in technicalities of publication.] 



Near low-water mark. Exuma Chain, Mariguana, and Caicos Islands : Florida, 

 Cuba, and Jamaica. Type from Cave Cays, Exuma Chain. 



