THE ALGAE OF BERMUDA. 29 



CLASS CHLOROPHYCEAE. 

 FAMILY DESMIDIACEAE. 



.CLOSTERIUM Nitzsch. 



1. Apices subacute; median diam. 17-37 p. 1. C. Leibleinii. 



1. Apices obtuse; median diam. 33-50 n- 2. C. moniliferum. 



*1. C. LEIBLEINII Kiitzing ex Ralfs, 1848, p. 167, PI. XXVIII, fig. 

 4; Wolle, 1884, p. 46, PI. VII, figs. 13, 14, 20; G. S. West, 1904, p. 141, 

 PI. XVI, figs. 9-14; P. B.-A., No. 2061. In small quantity in an 

 artificial reservoir for fresh water, near Spanish Rock, Dec., Hervey. 



*2. C. MONILIFERUM Ehrenberg ex Ralfs, 1848, p. 166, PL XXVIII, 

 fig. 3; Wolle, 1884, p. 45, PI. VII, fig. 15; G. S. West, 1904, p. 142, PL 

 XVI, figs. 15-16; P. B.-A., No. 1961. Very abundant in an artificial 

 reservoir for fresh water, near Spanish Rock, Dec., Hervey. 



COSMARIUM Corda. 



1. Uniformly granulate; semi-cell ovate-pyramidal, 51-68 n wide. 



4. C. botrytis. 



1. Smooth. 2. 



2. Semi-cell semicircular to semielliptic; 34-36 n broad. 1. C. Cucumis. 

 2. Semi-cell truncate-pyramidal, 19-30 n broad. 2. C. granatum. 



2. Semi-cell trapezoidal to truncate-pyramidal; about 33 n broad. 



3. C. pseudonitidulum. 



*1. C. CUCUMIS Corda ex Ralfs, 1848, p. 93, PL XV, fig. 2; G. S. 

 West, 1905, p. 152, PL LIX, figs. 18-20; P. B.-A., No. 1858. Among 

 Sphagnum in a ditch, Devonshire Marsh, April, Collins. Distributed 

 as C. subcucumis Schmidle, but agreeing better with C. Cucumis. 



*2. C. GRANATUM Brebisson in Ralfs, 1848, p. 96, PL XXXII, 

 fig. 6; Wolle, 1884, p. 60, PL L, fig. 13; G. S. West, 1905, p. 186, PL 

 LXIII, figs. 1-3. Rather scanty, among Ocdogonium Itzigsohnii, ditch 

 in Devonshire Marsh, April, Collins. 



*3. C. PSEUDONITIDULUM Nordstedt, 1873, p. 16, PL I, fig. 4; 

 Wolle, 1884, p. 62, PL XVIII, fig. 19; G. S. West, 1905, p. 195, PL 

 LXIII, fig. 26; P. B.-A., No. 2063. Among various algae in a ditch 

 in South Shore marshes, Sept., Collins. 



