132 COLLINS AND HERVEY. 



March, Gibbet Island, Dec, Her^'e;^•; Hungry Bay, April, Cooper's 

 Island, Aug., Little Agar's Island, Nov., Collins. On Gelidiuvi and 

 other algae, but most frequently on Sargassum; a careful search would 

 probably discover it in any lot of old Sargassum, but it is seldom found 

 in large quantity. 



Family CERAIMIACEAE. 

 Spermothamnion Areschoug. 



1. Cells 5-20 diam. long; tetraspores usually in corjTnbose clusters. 



3. S. macromeres. 

 1. Cells 2-7 diam. long; tetraspores solitary. 2. 



2. Filaments 15-20 n diam. 1. S. investiens. 



2. Filaments 40-50 /x diam. 2. S. gorgoneum. 



1. S. INVESTIENS (Crouan) Vickers, 1905, p. 64; Callithainnion 

 investiens Crouan in Maze & Schramm, 1870-1877, p. 141. On 

 Galaxaura squalida, Gravelly Bay, April, St. David's Island, April, 

 Collins; Harris Bay, Dec, Hervey. The dimensions of the Bermuda 

 plant agree with those given by Miss Vickers for the Barbados plant ; 

 Borgesen, 1909, p. 17, fig. 10, describes and figures var. cidaricola from 

 the Danish West Indies; the dimensions are considerably larger than 

 in the typical form, but the habit and the tetraspores are the same as 

 in the Bermuda plant. 



2. S. GORGONEUM (Mout.) Bomet in Vickers, 1905, p. 64; CaUith- 

 manion gorgoneum Montagne, 1857, p. 289. Common on fronds of 

 species of Codimn. Tetraspores with tripartite division were found 

 in Bermuda material, borne on an upcurved pedicel. 



3. S. macromeres sp. nov.; P. B.-A., No. 2044. Filamentis pros- 

 tratis circa 65 ii diam., cellulis 3-5 diam. longis, rhizoideis magnum 

 discum terminalem ferentibus, affixis; filamentis erectis 5-8 mm. 

 longis, basi circa 50 jj. diam., sensim diminutis, in ramis ultimis circa 

 30 /x; cellulis 5-20 diam. longis, cylindricis vel leviter clavatis, cellulis 

 ramiferis valide clavatis; ramificatione distante, apparenter dicho- 

 toma, axi ramoque subaequalibus, minime divergentibus; tetraspor- 

 angiis in ramo laterali evolutis, ramum vegetativum referente, vel in 

 ramis brevibus oppositis; ramis tetrasporangiferis raro simplicibus, 

 vulgo di- trichotome ad cellulam quamque repetite divisis, cellulis 

 brevibus, clavatis; tetrasporangiis terminalibus, tripartitis, 50-55 /x 

 diam., globosis vel paullo elongatis, membrana crassa; antheridio 



