SYNEDRA. 



311 



Valve linear, narrow, and excessively elongated (attaining 30 to 

 55 c.d.m.), with apices strongly capitate. 



Brackish water. Between Ostcnd and Blankenberghe (H.V. H.), Ard. Lieg. (DeWild.). 

 Ireland (Dickie). England (Norman in Baxter Coll., No. 2839). Scotland (Baxter Coll., 

 No. 2733). 



var. spathulifera Grun. (H.V.H. Atl., pi. 38, f. 4* ; in Type No. 

 25), plate 10, fig. 413. 



Linear, long ; apices somewhat dilated into a spatulate form. 



Fresh water. Deurne, near Antwerp. 



var. amphirhynchus. (S. amphirhynchus Ehr. ; H.V.H. Atl., pi. 38, 

 f. 5*), plate 10, fig. 414. 



With apices rostrate-capitate. 



Fresh water, Ard. Lieg. (De Wild.). Ireland (O'Meara). 



var. Danica. (S. Danica Kiitz. ; H.V.H. Atl., pi. 38, f. 140*), plate 

 10, fig. 415. 



Long, and very narrowly lanceolate, with apices rostrate capitate. 



Fresh water. Ard. Lieg. (DeWild). 



var. lanceolata. (S. lanceolata Kiiiz. ; H.V.H. Atl., pi. 38, f. 10*), 

 plate 10, fig. 416. 



Narrowly lanceolate, and infinitesimally attenuate up to the apices. 



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



var. obtusa. (S. obtusa W. Sm. ; H.V.H. Atl., pi. 3S, f. 6*), plate 

 10, fig. 417. 



Linear, rather broad, with obtuse apices. 



Fresh water. England (W. Sm., Stolt., Comber, Kitton in Baxter Coll., No. 4305). 



var. oxyrhynchus. (S. oxyrhynchus Kutz.) H.V.H. Atl., pi. 39, f. in*), 

 plate 10, fig. 418. 



Small (7 to 8 c.d.m. mean), linear, with apices infinitesimally attenuate 

 into a rather broad rostrum ; striae somewhat closer, about 10 in 1 c.d.m. 



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



var. vitrea. (S. vitrea Kutz. ; H.V.H. Atl, pi. 38, f. 11 and 12*), 

 plate 10, fig. 419. 



Valve linear, narrow, with apices longly and narrowly rostrate ; striae 

 extending throughout the valve. 



Fresh water. Ard. Lieg. (De Wild.). 



S. ACUS (Kutz.) Grun. (Wien, 1862, p. 398; S. oxyrhynchus IV. 

 Sm. nee Kutz. ; H.V.H. Atl., pi. 39, f. 4* ; in Type No. 479), plate 10, fig. 

 420. 



