562 SPHAEKOCOCCACEAE. 



5. WURDEMANNIA Harv. Ner. Bor.-Am. 2: 245. 1853. 



1. Wurdemannia setacea Harv. loc. cit. 246. 



On rocks among other algae and on sea-rods, sea-fans, etc., from low-water mark 

 down to at least 20 meters, common. Joulter's Cay, Berry Islands, Great Bahama. 

 South Cat Cay, Exuma Chain, Atwood Cay, and Caicos Islands : Bermuda ; Florida ; 

 and Cuba. Type from Key West, Florida. 



Family 7. SPHAEROCOCCACEAE. 



1. GRACILARIA Grev. p. p. Alg. Brit, liv, 121. 1830. 



Ceramiantemum Donati, Auszug Natur-Geschichte Adriat. Meers 26. 1753. 



Ceramion Adans. Fam. PI. 2: 13. 1763. 



? Plocaria Nees, Hor. Phys. Berol. 42. 1820. 



Thallus plane or distinctly compressed, di-polychotomous or more or less pinnate. 

 Membranaceous when dry : main axes or segments mostly 0.3-1 mm. thick. 

 Thallus dichotomo-palmatifld, marginal branches or pro- 

 liferations usually wanting or few. 1- G. lacinulata. 

 Thallus with main divisions subdichotomous, these pin- 



nately decompound or repeatedly dichotomo-pinnatisect. 2. G. cervicornis. 



Hard and corneous when dry, cartilaginous when living, mostly 



2-7 mm. thick, prostrate or repent, often concrescent or 



anastomosing, branches irregular, mostly distichous and 



deflexed. often short and verrucaeform, sometimes sub- 



terete, digitiform or hapteroid. 3. G. crassissima. 



Thallus terete or nearly so, corneous when dry. 



Thallus rather closely and somewhat divaricately subdichot- 

 omous, the ultimate divisions short, often incurved, cervi- maecomis 



Thallus rather distantly and somewhat fastigiately subdichot- 



omous, the ultimate divisions not cervicorn. 5 - cornea. 



1. Gracilaria lacinulata (Vahl) M. A. Howe, comb. nov. 



Fucus lacinulatus Vahl, Nat. Selsk. Skr. 5 2 : 39. 1802. 



Fucus multipartitus Clem. Ensayo 311. 1807. 



Chondrus agathoicus Lamour. Essai 39. pi. 9. f. 3, 4, 5. 1813. 



Fucus aeruginosus Turn. Hist. Fuc. 3: 29. pi. 147. 1811. 



Chondrus aeruginosus Lamour. Essai 40. 1813. 



Sphaerococcus polycarpus Grev. Scot. Crypt. Fl. 6: pi. 352. 1828. 



Gracilaria multipartita Harv. Phyc. Brit. pi. 15. 1846. 



Sphaerococcus lacinulatus Kiitz. Tab. Phyc. 18: 30. pi. 87. f. a-d. 1868. 



In shallow water. Berry Islands : Massachusetts to Bermuda ; Florida ; Mexico ; 

 and throughout the West Indies ; Europe. Type from St. Croix. 



? Gracilaria cervicornis (Turn.) J. Ag. Sp. Alg. 2: 604. 1852. 



Fucus cervicornis Turn. Hist. Fuc. 2: 132. pi. 121. 1809. 

 Sphaerococcus domingensis (Sond.) Kiitz. Tab. Phyc. 19: 8. pi. 2,2. f. a, b. 

 1869. 



In shallow water, New Providence and Caicos Islands : Florida to Brazil. Type 

 from Jamaica. 



3. Gracilaria crassissima Crouan; J. Ag. Sp. Alg. 3 4 : 78. 1901. 



? Gracilaria horizontalis Collins & Hervey, Proc. Am. Acad. 53: 111. 1918. 



Forming prostrate, crust-like, intertangled masses in shallow water, Berry Islands, 

 North Cat Cay, South Cat Cay, and Mariguana : Bermuda (?); Porto Rico; and 

 Guadeloupe. Type from Guadeloupe. 



