^ 







SYNEDRA. 3 I 3 



S. investiens W. Sm. ! (S.B.D., ii., p. 98; H.V.H. Atl., pi. 40, 

 . 3* ; Type No. 293), plate 10, fig. 425. 



Valve narrowly linear-lanceolate, often slightly gomphonemoid ; striae 

 very robust, about 9 in 1 c.d.m. Length, 1 '5 to 4 c.d.m. 



Marine. Ostend (Westendorp. No. 797), England (Kitten), Ireland (O'Mearal, Scot 

 (Grev.). 



S. barbatula Kutz. ! (Bac., p. 68, pi. 15, f. 107; h.v.h. Atl., 



pl. 40, f. 6A* ; Type No. 294), plate 10, fig. 426. 



Valve small, rather broadly lanceolate, with apices slightly rostrate. Raphe 

 narrow. Striae delicate, about 18 in r c.d.m. Length, 2 to 2*5 c.d.m. 



Marine. Not yet observed in Belgium. England. Ireland (O'Meara). 



<v. Valves with apices rostrate-capitate. Fresh water species. 



S. capitata Ehr. (inf., pi. 21. f. 29; H.V.H. Atl., pL'38, f. 1* ; 

 Type No. 283), plate 10, fig. 427. 



Valve linear, with apices strongly capitate, head triangular, with a somewhat 

 attenuated termination. Pseudo-raphe narrow, terminated by obscure nodules. 

 Striae robust, 8 in 1 c.d.m. Length, 20 to 50 c.d.m. 



Fresh water. Rather common everywhere. 



S. famelica Kutz. ! (Bac, p. 64, pi. 14, f. vin. 1 ; h.v.h. Atl., 

 pl. 39, f. 17*), plate 10, fig. 428. 



Valve rather broadly lanceolate, with apices strongly rostrate-capitate. 

 Pseudo-raphe narrow. Striae delicate, 21 in i c.d.m. Length, 2^5 to 3 c.d.m. 



Fresh water. Not yet found in Belgium. 



S. amphicephala Kiitz.! (Bac, p. 64, pl 3, f. 12; h.v.h. Atl., 



pl. 39, f. 14* ; var. in Types Nos. 30. 128 and 332), plate 10, fig. 429. 



Valve very narrowly lanceolate, with apices strongly rostrate-capitate. 

 Pseudo-raphe very distinct. Striae very robust, about 11 in 1 c.d.m. Length, 

 4 to 6 c.d.m. 



Fresh water. Ard. Lieg. (De Wild.), Scotland, Ireland. 



