ADDENDA. 269 



Cosmarium Brebissonii Menegh (vol. iii. p. 161). 



The zygospore of CoxtHfm'mn Brebissonii has been figured by 

 Harris in ' Journ. Quek. Micr. Club.' 1917. 1. 19, f. 10, from Devon- 

 shire. It is spherical, about 5<> n in diameter, and covered with 

 broad rounded tubercles, about 14 of which are to be seen round 

 the periphery. 



Genus STAURASTRUM Meven. 



i 



Staurastrum Meriani Eeinsch (vol. iv, p. 122). 

 (PL CLXV1I, figs. 8, 9.) 



Zygospore compressed, circular in front view, with 

 10-12 marginal crenations. Diam. 4.V.5 u ; thickness 

 27 p.. 



[This zygospore is almost identical with that of St. striolatum 

 (Niig.) Arch., see vol. iv. PL CXXVII, figs. 3-5.] 



Staurastrum brevispinum Bivb. (vol. iv. p. 145). 



(PL CLXYL fig. 2.) 

 Zygospore spherical, membrane smooth. Diam. 45 p. 



[These zygospores were found by Mr. \V. J. Hodgetts, from 

 whose preparations the figure given was made.] 



ADDITIONAL SYXOXYMS. 



CLOSTERIUM CERATIUM Pertv (vol. i, p. 17(3), includes Cl. fasciculatum 



Rabeiih. Alg. Ear. no. 2163, 1870. 

 EUASTRUM BENALE (Turp.) Ehr. f. GUTWIXSKII Schmidle (vol. ii, p. 53) 



includes Eu. venustum Hantzscb, Rabenh. Alg. Eur. no. 1543, 1863. 

 COSMARIUM SPECIOSUM Lund. 1870 (vol. iii. p. 247) includes C. 



Heuflerianum Grim, in Rabenh. Flor. Eur. Alg. 1868, p. 172; De Toni,. 



Syll. Alg. 1889, p. 1053. 



