ENCYONEMA. 



'5' 



Valve cymbiform, with dorsum arcuate, ventral margin slightly concave 

 with apices sub obtuse. Striae very well marked, distant, to in i c.d.m., 

 leaving off everywhere at a short distance from raphe. Length, about 3 c.d.m. 

 Breadth, 1*5 c.d.m. in the middle portion. 

 Fresli water. England, Scotland, Braerrrai (Di Balfour) W. Sm. ! 



E. gracile Rabh. (Sussw. Diat, p. 25, pL io,Suppl. f. 1 ; ii.v.h. 

 Atl., pi. 3, f. 20,*) plate 28, fig. 791, bis. b. 



Dorsal margin arcuate; ventral margin inflated al the median portion. 

 Striae delicate, about 12 to r} in 1 c.d.m., leaving an elongated hyaline area 

 round the central nodule. Length about 6 to 8 c.d.m. ; breadth, about 1 c.d.m. 

 Freshwater. Germany (Rabenhorst) ; Wesl Ireland (West). 



Var. Scotica (CymM/a Scotica. W. Sm. S.B.D. i., p. 18, pi. 2, f. 25 ; 

 ii. p. 84. II.V.H. Atl., pi. 3, f. 21* j in Type No. 2741, plate 28, fig. 

 791, bis. a. 



Ventrai margin straight, not inflated at the median portion ; median 

 striae on dorsal side appearing to coal ( ce in the central nodule. Striation 

 and size as in type form. 



Fresh water. Ard, Lfe| i l" Wild), England, Scotland, vai 



