366 DESMIDEJE. 



7. COSMARIUM OVALE Raljs. 



Plate LXXXVI. Figs. 8. and 9. 



Chai\ Fronds large, compressed, punctated. Segments tri- 

 angular, slightly truncate at the extremity. End view 

 broadly elliptic. 

 /3 Segments dentated, 



Cosmarium ovale Ralfs, in Annals, vol. xiv. pi. xi. fig. 7. — 

 /3. Euastrum No. 6. Bailey, 1. c. p. 295. fig. 28. ; Jen- 

 ner, in loc. cit. p. 196. 

 Hab. Dolgelly : Mr. Ralfs. Barmouth : Rev. T. Salwey. 

 Near Tunbridge Wells, in a pond between Eamlye and 

 Broadwater Forest ; Beckley Furnace : Mr. Jenner. — 

 /3. Weston bogs, near Southampton : Mr. Jenner. 



The characters of the different species of Desmidem may 

 generally be so accurately embodied in the definition as to 

 preclude the necessity of any lengthened remarks attached to 

 each species ; this conciseness it is to be hoped as our know- 

 ledge of the works of creation becomes more extensive, will 

 be found applicable to the descri^^tion of all organised pro- 

 ductions. 



8. Cosmarium Cucumis Corda. 



Plate LXXXVI. Fig. 10. 



Char. Fronds orbicular, ?mich compressed. Segments hemi-^ 

 spherical, quite smooth, being neither denticulated nor dotted. 

 End view elliptico'lanceolate. 



Menegliini, Synops. Desmld. p. 220. Euastrum integerri- 

 mum Ehr., Infus. p. 163. tab. 12. fig. 9. Cosmarium 

 Cucumis Corda, Almanac de Carlsbad, 1835, p. 206. 

 tab. 11. figs. 27, 28. C. Cucumis Ralfs, 1. c. p. 395. pi. xi. 

 fig. 8.; Jenner, in loc. cit. p. 196. 



Hab. Sussex : Mr. Jenner. Dolgelly : Bfr. Ralfs. 



The frond is more orbicular and not punctated as in Cos- 

 marium ovale. 



