EHODOMELACEAE. 569 



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



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

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

 Acanthophora Thierii Lamour. Essai 44. 1813. 

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



Acanthophora AntiUarum Mont. Klitz. Tab. Phyc. 15: 27. pi. 75. f. d-g. 

 1865. 



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

 Bimini, Exuma Chain, NVatlin^'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. 2^/. 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. loc. cit. 389. 



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

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

 Digenea Wulfeni Kutz. 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 

 Sovith 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. xx\-i. 1817. Not Hutchixsia R. Br. 1812. 

 Vertebbata 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. 1823; 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 u in diameter; plants 

 soft and mucous, reddish purple, branches 



fastigiate. 2. P. havancnsis. 



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. Binnciji. 

 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.fcrulacea. 



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