590 EXCOELIACEAE. 



The filaments are mostly 25-40 # in diam., while Grunow's description of the 

 type makes the diameter only 11-25 #, but as the base of one of the filaments 

 figured by Grunow is nearly 35 fj. broad it seems difficult to distinguish the Bahamian 

 plant. The later-described P. fitlvescens (Schonsb.) Bornet may be a synonym, but 

 perhaps differs in the more protuberant, sometimes laterally geminate sporangia. 



2. ECTOCARPUS Lyngb. Hydroph. Dan. 130. 1819. 



1. Ectocarpus Mitchellae Harv. Ner. Bor.-Am. 1: 142. pi. 12G. 1852. 



On Thala-ssla, etc., in shallow water. Berry Islands, Great Bahama, and Exuma 

 Chain : Massachusetts to American Virgin Islands : apparently widely distributed 

 in temperate and tropical seas. Type from Nantucket, Mass. 



Family 2. SPHACELARIACEAE. 





 1. SPHACELARIA Lyngb. Hydroph. Dan. 103 p.p. 1819. 



1. Sphacelaria tribuloides Menegli. Lett, al Corinaldi 2. 1840. [Not seen.] 



Low-littoral. Berry Islands : Bermuda to Mexico and Barbados ; widely dis- 

 tributed in the warmer seas. Type from Italy. 



Family 3. ENCOELIACEAE. 



1. PHAEOSTROMA Kuckuck, in Eeinbold, Schrift. Naturwiss. Ver. 



Schleswig-Holst. 10: 43. 1893. 



1. Phaeostroma pusillum Howe & Hoyt, Mem. N. Y. Bot. Gard. 6: 109. pi. 11. 

 f. 1-9. 1916. 



Making minute discs, 0.150.35 mm. in diameter, on Polysiplionia ferulacea; the 

 unilocular sporangia mostly in sori. Berry Islands: North Carolina (type). 



2. COLPOMENIA (Endl.) Derb. & Sol. Mem. Phys. Alg. 11. 1856. 



]. Colpomenia sinuosa (Roth) Derb. & Sol. loe. eit. [C. sinuata by misprint.] 



Ulva sinuosa Eoth, Cat. Bot. 3: 327. pi. 12. 1806. 

 Encoelium sinuosum Ag. Sp. Alg. 1: 146. 1820. 

 Asperococcus sinuosus Bory, Exped. Sci. Moree 3 2 : 326. 1832. 

 Hydroclathrus sinuosus Zanard. ; Mitchell, in Murray, Phye. Mem. 53-56. 

 1>L 14. pi. 15. f. 1. 1893. 



On rocks near low-water mark or in shallow water. Gun Cay : Bermuda and 

 Florida to Brazil ; Peru ; widely distributed in warm-temperate and tropical seas. 

 Type from near Cadiz, Spain. 



3. HYDROCLATHRUS Bory, Diet. Class. Hist. Nat. 8: 419. 1825. 

 1. Hydroclathrus clathratus (Bory) M. A. Howe, comb. nov. 



Encoelium dathratum (Bory) Ag. Sp. Alg. 1: 412. 18-22. 

 Hydroclathrus cancellatus Bory, Diet. Class. Hist. Nat. 8: 419. 1825. 

 StUopliora clatlirata Ag. Flora 10: 642. 1827. 

 Asperococcus datJiratus J. Ag. Sp. Alg. 1: 75. 1848. 



On rocks near low-water mark or in shallow water. Gun Cay and North Cat 

 Cay : Bermuda and Florida to Brazil ; widely distributed in warm-temperate and 

 tropical seas. Type from Belle Isle, France. 



