3<D2 EUNOTIA. 



Valve small, narrow, with apices capitate ; ventral margin level, slightly 

 concave, dorsal margin with three slight elevations; striae delicate, about 15 

 in 1 c.d.m. Length, about 2 c.d.m. 



Fresh water. Paliseul (Del.). Ard. Lieg. (De Wild.). Rare. England (H. V.H.), Scotland. 



E. praerupta Ehr. (Amer., p. 126; h.v.h. Atl., pi. 34, fig. 19*) 

 plate 9, fig. 376. 



Valve robust, elongate, with apices attenuate, subcapitate, truncate ; dorsal 

 margin rather strongly arcuate ; ventral margin almost straight ; stria; very 

 narrow, distant, about 6 in i c.d.m. in the middle of the valve, very compact 

 at the apices, finely punctate ; terminal nodules very coarse. Girdle face 

 quadrangular, showing about 12 very delicate stria; at the median portion. 

 Length, 4 to 8 c.d.m. 



Fresh water. Not yet found in Belgium, and probably not indigenous. Northern Europe. 



forma curta. (H.V.H. Atl., pi. 34, f. 23 and 24*), plate 9, fig. 377. 

 Scarcely attaining 3 c.d.m. 



var. inflata Grun. (H.V.H. Atl., pi 34, 1. 17*), plate 9, fig. 378. 



Valve broader, with more inflated dorsum. 



var. bidens Grun. (E. bidem {Ehr.) IV. Sm. ; H.V.H. Atl., pi. 34, 

 f. 20* ; in Types No. 98, 548), plate 9, fig. 379. 



Valve very large and very broad, with dorsum showing a median 

 inflexion. 



Fresh water. England (Norman), Ireland (O'Meara). 



var. bigibba. (E. bigibba Kuiz. ; H.V.H. Atl., pi. 34, f. 26* ; in Type 

 No. 62), plate 9, fig. 380. 



Valve short, squat, with apices abruptly constricted on the dorsal 

 margin ; with dorsum bearing two strong ridges ; ventral margin very 

 concave. 



Fresh water. Frahan (Delogne). 



E. bidentula W. Sm. (S.B.D., ii., p. 83 ; H.V.H. Atl., pi. 34, 

 f. 28*), plate 30, fig. 828. 



Valve of medium or small size, with ventral margin almost straight, dorsal 

 margin showing two rounded or somewhat acute elevations, apices strongly 

 attenuate, capitate ; terminal nodules very distinct ; striae very delicate, about 

 15 in 1 c.d.m., finely punctate Length 2^5 to 4 c.d.m. 



Freshwater. England: Fellend near Lancaster (Johnson !), Scotland: Braemar (Balfour !) ; 

 Arran (Arnott !) ; Barley Lough (W. Sm. !) ; Ben Nevis (Greg. !), etc. 



