382 DESMIDEJE. 



5. EUASTKUM AFFINE Ralfs. 



Plate XC. Fig. 9. 



Char. Frond about three times as long as broad. Segments 

 pyramidal in front view, and thrice emarginate ; in lateral 

 view twice emarginate. 

 ft Frond about once and a half as long as broad, twice 



emarginate. 

 Euastrum affine Ralfs, in Annals, vol. xiv. pi. vii. fig. 3. 



Hob. In peat pools near Dolgelly : Mr. Ralfs. High 

 Beech: A.H.H. Aberdeen; Dr. Dickie. 



Fronds about as large as those of Euastrum Didelta ; the 

 segments somewhat resemble a decanter in form ; the base 

 is broad and inflated, and contracted upwards into a wide neck ; 

 the terminal notch is deep but not gaping ; the body of the 

 segment is broadly emarginate on each side ; all the lobes or 

 projections are rounded and the sinuses shallow. 



The var. j3 is probably distinct. 



6. EUASTRUM GEMMATUM Ralfs. 

 Plate XCI. Fig. 6. 



Char. Frond rather more than twice as long as broad. Seg- 

 ments in front view scarcely emarginate at their extremi- 

 ties, laterally twice so ; in transverse view eight-lobed, 

 longer than broad ; and in end view four-lobed. 



ft Terminal lobe emarginate at each side. 



Cosmarium gemmatum Breb., Menegh. 1. c. p. 221. Euas- 

 trum gemmatum Ralfs, Ann. vol. xiv. p. 191. pi. vii. 

 fig. 4. ; Jenner, in Flor. Tunbridge Wells, p. 198. 



Hab. Near Dolgelly : Mr. Ralfs. Scrubbs, Colebrook 

 Park, and on Ashdown Forest, in the great bog near 

 Forest Row : Mr. Jenner. 



"Fronds rather smaller than those of E. Didelta, nearly 

 three times as long as broad. Each segment consists of a broad 

 basal portion which is somewhat quadrilateral and emarginate 



