134 AMPHORA. 



A. acutiuscula Kutz. (Baa, p. 108; H.V.H. Atl., pi. i, f. 13* 

 in Type No. 261), plate 1, fig. 5. 



Frustules elliptic or elliptic-lanceolate, with apices slightly rostrate, 

 truncate. Valve with dorsal margin arcuate, ventral margin slightly inflated ; 

 apices rostrate-capitate; raphe straight, striae with distinct puncta, 13 to 14 in 

 1 c.d.m. on dorsal side, 18 to 20 on ventral side. Length, about 5 c.d.m. 



Marine. Blankenberghe ; North Sea. 



A. salina W. Sm. (s.B.D. L, p. 19, pi. 30, f. 251 ; H.V.H. Atl., 



pi. 1, f. 19*; Type No. 11), plate 1, fig. 6. 



Frustule elliptic-oblong with apices slightly produced, truncate. Valves with 

 apices rostrate, slightly capitate ; dorsal margin arcuate, ventral margin 

 straight or concave ; raphe concave with reference to the connecting zone ; 

 striae fine, punctate, 18 to 21 in 1 c.d.m. on the dorsal side, 20 to 21 on 

 ventral side. Length, 3 to 5 c.d.m. 



Brackish water. Common at Antwerp, Blankenberghe, Heyst ; England ; Scotland ; Ireland ; 

 Denmark ; and probably throughout the shores of the North Sea. 



ft minor. (A. borealis Kutz! Baa, p. 108, pi. 3, f. 18; H.V.H. 

 Atl., pi. i, f. 20*), plate 1, fig. 7. 



Smaller and broader, with a not very pronounced beak. 



Slightly brackish water Blankenberghe. 



A. coffeseformis Kiitz. ! (Baa, p. 108, pi. 5, f. 27 ; Ad. Sch. 

 Atl., pi. 26, f. 56, 58, 59*) plate 24, fig. 681. 



General appearance resembling that of A. Salina, but frustules tapering 

 infinitesimally to apices, which are generally very slightly produced. 

 Valves with apices rostrate, very slightly capitate. Transverse stride 

 excessively delicate and almost invisible. Longitudinal striae few but very 

 distinct. 



Brackish and Marine. Shores of North Sea 



A. veneta Kiitz. (Baa, p. 108, pi. 3, f. 25 ; H.V.H. Atl., pi. 1, 

 f. 17*; Type No. 10) plate I, fig. 11. 



Frustule oblong-elliptic, with apices slightly truncate. Valves with dorsal 

 margin convex, infinitesimally attenuate ; ventral margin flat or slightly 

 concave ; raphe concave ; central nodule elongated ; striae fine, about 

 20 in t c.d.m., slightly more robust in median portion. Length, 2 to 

 3 c.d.m. 



Brackish water. Blankenberghe, Antwerp. 



