BERKELEYA. 



245 



GENUS 18. BERKELEYA (GREV. 1827), H. VAN HEURCK, 



Emend. 



Valves with central nodule sub-divided, divisions more or less 

 separated. Raphe absent between the divisions of the nodule. 

 Frustules naviculoid, enclosed in mucous tubes as in the Schizonema. 



ANALYSIS OF SPECIES. 



f r ('About 32 strife in i c.d.m. B. fragilis. 



Valves sublinear, narrow ; strire quite parallel \ 



( About 26strire in 1 c.d. m. B. micans. 



. Valves elliptical-lanceolate, median strire parallel, terminal radiate . . B. Dillwynii. 



OT 



s 



I 



B. fragilis Grev. (Scot. Crypt. Flor. pi. 

 294 ; H.V.H. Atl., pi. 16, f. 12). 



Valves linear, narrow, and very elongated ; sub- 

 divisions of central nodule rather approximate ; striae 

 quite parallel, delicate, 32 to 40 in 1 c.d.m. Length, 

 about 8 c.d.m. Breadth, about 0-4 c.d.m. 



Marine. Not yet discovered in Belgium. England (Mrs. Griffiths). 

 Scotland (Grev., Arnott), Eulen, Type No. 80. Ireland (O'Meara). 

 France, Brest (Coronan) ; Cherbourg (Bre'bisson). 



Prof. Cleve makes B. fragilis only a variety of the 

 following : 



B. micans (Lyng.) H.V.H. (H.V.H. 

 Atl., pi. 16, f. n* ; Type No. 156), plate 5, fig. 254. 



Valves linear, narrow and very elongated ; sub- 

 divisions of central nodule rather distant ; striae 

 parallel, delicate, 26 in 1 c.d.m. Length, 8 to 9 c.d.m. 

 Breadth, 0-4 c.d.m. 



Marine. Not yet discovered in Belgium, but found in France, 

 Holland and Denmark. 



Fig 45 B. Dillwynii (Agardh) H.V.H. (H.V.H. 



Berkeleya fragilis. Atl., pi. 1 6, f. 1 5* J Type No. 157), plate 5, fig. 255, 



Valves elliptical lanceolate, narrow, with divisions of central nodule more 

 or less distant. Median striae parallel, terminal radiate, delicate, 30 in 1 

 c.d.m. Length, 1*5 to 3-5 c.d.m. Breadth, C4 to o - 6 of c.d.m. 



Marine. Ostend (West. 895 sub. Schizonema rutilans). Ostend leg. (Grunow). England 

 (Kitton), Scotland (Eulen, Type No. 81, 82). 



