COSMARIUM. 47 



the poles. Cell-wall smooth. Chloroplasts axile, with 

 one central pyrenoid in each semicell. 



Zygospore unknown. 



Length 13-18 p. ; breadth 14-18 p.; breadth of 

 isthmus G-7'5 p.; thickness 9-12 //,. 



SCOTLAND.- -Poolewe, Ross; Brin, Inverness (Roy $ 

 Bissett). 



IRELAND. --G-len Caragli, Kerry ! 



Geoyr. Distribution.- -Austria and Galicia. 



This species should he compared with Cosmarium monochon- 

 druin Nordst., from which, however, it is easily distinguished. 



Var. subundulatum ^Y. & G. S. West. (PI. CIII, 



fig. :3.) 



C.prominulum var. subundulatum W. & G. S. West, New Brit. Freshw. 

 Alg. 189-4, p. 6, t, 1, f. 16. 



Semicells with the apex slightly 3-4-undulate, and 

 with the superior lateral margins binndulate (one crest 

 and two hollows) ; vertical view with a more conical 

 median protuberance on each side, with the tumours 

 near the poles larger, and with the poles more markedly 

 mamillate. 



Length 16-18 //,; breadth 17-19 p. ; breadth of 

 isthmus 8 9' op.; thickness 13*5 /A. 



ENGLAND.- -Elter Water, Cumberland ! 



Liitkemiiller has described from Austria (' Desm. Millstat- 

 tersees/ 1900, p. 10, t. 1, f. 28-30) a forma ornata of this 

 variety, to which is also referable the Desmid described by 

 Messrs. Eichler & Gutwinski as Cosmarium sculptum (vide 

 Eichler & Ghitw. 'Noun. spec. alg. nov/ 1894, p. 169, t. 4, 



f 99\ 

 i. j . 



SPECIES TO BE ENQUIRED INTO. 



COSMARIUM CRUCIATUM Breb. Liste Desm. 1856, p. 129, t. 1, 

 f. 14; Rabenh. Flor. Europ. Alg. Ill, 1868, p. 168; Kirclm. 

 Alg. Schles. 1878, p. 153; Wolle, Desm. U. S. 1884, p. 81. 

 t. 18, f. 23, 24; Haus^. Prodr. Algenfl. Bohm. 1888, p. 201, 

 251 ; De Toni, Syll. Alg. 1889, p. 1014 ; Roy & Biss. Scott, 

 Desm. 1894, p. 44; Nordst. Index Desmid. 1896, p. 90. 



