COSMAEIUM. 7 



Length 65-70 p. ; breadth 55-59 //,; breadth of 

 isthmus 15 //, ; thickness 25-27 /x. 



ENGLAND.- -Near Ingleton, AY. Yorks! Strensall 

 Common, N. Yorks ! Xear Brigg, Lincolnshire ! Lord's 

 Bridge, Cambridgeshire ! Esher West-end Common, 

 Surrey ! Hayes Common, Kent ! 



IE ELAND.- -Churchill, Donegal! Xear Westport, 

 Mayo ! Xacoogarrow Lough, and between Clifden and 

 Roundstone, Gal way ! Clogerheen, Kerry ! 



Geogr. Distribution.- -Germany. 



This variety should be compared with C. Botnjtis var. 

 iiiesoleium Nordst. ('Desm. ItaV 1876, p. 27, t. 12, f.' 2), from 

 which it is distinguished by its proportionately wider semicells, 

 by the absence of the small central protuberance, and by the 

 absence of the granules above the isthmus. 



Var. depressum W. & G. S. West. (PI. XCVII, fig. 6.) 



C. Botrytis var. depressum W. & Gr. S. West, Further Contrib. Plankton 

 Scott. Lochs, 1905, p. 500, t. 7, f . 1 ; Comp. Study Plankton Irish Lakes, 

 1906, p. 85. 



Cells shorter than in the type, about as long as 

 broad ; semicells depressed, basal part very wide and 

 basal angles very broadly rounded, apical angles very 

 obtuse. 



Length 68-72 ^ ; breadth 65-68 //, ; breadth of 

 isthmus 1 6-1 7 p.. 



SCOTLAND.- -Plankton of Loch Ruar, Sutherland ! 



IRELAND.- -Plankton of Lough Corrib, G-alway ; and 

 of Lough Caragh, Kerry ! 



We have only met with this depressed variety in the 

 plankton. 



It is possible that C. Hyacinthi Gutw. ('Flor. Glon. Okolic 

 Lwowa/ 1891, p. 62, t. 2, f. 30) is closely related to this 

 variety, but Griitwinsld's figure is not very good. The only 

 distinction appears to be the presence of a central tumour in 

 the Galician form. 



226. Cosmariutn Gayanum De Toni. 

 (PL GUI, figs. 5, 6.) 



Euastrum (Cosmarium) ellipticum Gay, Mon. loc. Conj. Montpellier, 1884, 

 p. 63, t. 2, f. 5 [not C. ellipticum Delp., 18771 ; Note Conj. du midi 

 de France, 1884, p. 337. 



