EHODOMELACEAE. 569 



1. Acanthophora spicifera (Vahl) Borg. Bot. Tidsskr. 30: 201. /. 18, 19. 1910. 



Fucus spiciferus Vahl, Nat. Selsk. Skr. 5 2 : 44. 1802. 

 Fucus acanthophorus Lamour. Diss. 61. pi. 30; pi. 31. f. 1. 1805. 

 Acanthophora Thierii Lamour. Essai 44. 1813. 

 Chondria acanthophora Ag. Spec. Alg. 1: 363. 1822. 



Acanthophora Antillarum Mont. Kiitz. Tab. Phyc. 15: 27. pi. 75. f. d-g. 

 1865. 



In shallow water, especially in sheltered bays, New Providence, Rose Island, 

 Bimini, Exuma Chain, Watling's Island, Mariguana, and Great Ragged Island : 

 Bermuda ; Florida ; to Barbados and Brazil. Type from St. Croix. 



2. Acanthophora muscoides (L.) Bory, Voy. Coquille, Bot. Crypt. 156. 1828. 



Fucus muscoides L. Sp. PI. 1161. 1753. 



Acanthophora militaris Lamour. Essai, 44. pi. 4. f. 4, 5. 1813. 

 Chondria muscoides Ag. Sp. Alg. 1: 361. 1822. 



Acanthophora Delilei Harv. Ner. Bor.-Am. 2: 18. 1853. Not A. Delilei 

 Lamour. Essai, 44. 1813. 



In shallow water, Great Bahama : Florida to Brazil and Ascension Island. 

 Type from Ascension Island. 



4. DIGENEA Ag. Sp. Alg. 1: 388. 1822. 

 1. Digenea simplex (Wulf.) Ag. loe. cit. 389. 



Conferva simplex Wulf. Crypt. Aquat. 17. 1803. 

 Fucus Lycopodium Turn. Hist. Fuc. 4: 6. pi. 199. 1819. 

 Digenea Wulfeni Kiitz. Phyc. Gen. 433. 1843. 



In tide-pools and in shallow water, New Providence, Great Bahama, Bimini, 

 Exuma Chain, Mariguana, and Great Ragged Island : Bermuda and Florida to 

 South America ; widely distributed in the warmer seas. Type from Trieste. 



5. POLYSIPHONIA Grev. Fl. Edinb. 308. 1824. 



? POLYOSTEA Donati, Auszug Natur-Ges. Adriat. Meers 22. 1753. 

 HUTCHINSIA Ag. Syn. Alg. Scand. xxvi. 1817. Not HUTCHINSIA E. Br. 1812. 

 VERTEBRATA S. F. Gray, Nat. Arr. Brit. PL 1: 338. 1821. 

 GRAMMITA Bonnem. Jour. Phys. 94: 186. 1822. [Not seen.] 

 GRATELOUPELLA Bory, Diet. Class. Hist. Nat. 3: 340. 18'23; 7: 480. 1825. 

 DICARPELLA Bory, loc. cit. 3 : 340. 1823 ; 5 : 464. 1824. 

 CARRADORIA Mart. Fl. Bras. Acot. 15. 1833. 

 GRAMMITELLA Crouan, Ann. Sci. Nat. Bot. III. 10 : 372. 1848. 



Pericentral cells four. 



Uncorticated or with few and inconspicuous cortical cells in older parts. 

 Trichoblasts ("hairs," "leaves") apparently wanting; 

 plants blackish purple, usually not adhering well to 



paper on drying. 1. P. subtilissima. 



Trichoblasts manifest, few or numerous. 

 Branching obviously monopodial. 



Lateral branchlets arising in the axils of tricho- 

 blasts. 



Main axes mostly 50-90 a in diameter ; plants 

 soft and mucous, reddish purple, branches 

 fastigiate. 2. P. havanensts. 



Main axes mostly 100-300 u. in diameter; 

 plants firmer, brownish purple ; branches 

 not fastigiate, very irregular, or the ulti- 

 mate ramuli sometimes short and alternate- 

 distichous or pseudo-distichous. 3. P. Binneyi. 

 Lateral branchlets arising without apparent ref- 

 erences to the trichoblasts ; segments often 

 shorter than broad, outer cell walls in adult 

 parts commonly 12-40 w thick. 4. P.ferulacea. 



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