128 AMPHORA. 



Very small. Frustule oblong or subglobose, rather truncate at apices. 

 Valve very convex at dorsal margin, straight at ventral margin ; raphe 

 straight, scarcely concave, spurious stauros just visible ; striae very delicate, 

 numbering from 9 to 10 in 1 c.cl.m. ; length less than 1 c.d.m. 



Moist wa'l at Botanical Gardens, Brussels, associated with A. Normanii (Del). 

 This form should probably be referred to A. ovalis var Pediculus. 



A. Normanii Rabenh. (Fi. Eur. Aig., p. 88. A. humkola 



Gntn in H.V.H. Atl., pi. i, f. 12*; Type No. 5) plate 1, fig. 4. 



Frustule elliptic with apices slightly rostrate-truncate. Valve with 

 raphe slightly inflexed, showing a stauro-form blank space ; apices 

 rostrate-capitate; striae fine, punctate, from 16 to 18 in 1 c.d.m. at the 

 dorsal portion of valve, very fine, about 24 in 'or at ventral m 11 gin. 

 Length, 2.5 to 3 c.d.m. 



On a moist wall at Botanical Gardens, Brussels (Del); Hull, England (Norman). 



A. dubia (Greg, 1857?) Ad. Schm, 1875 (At, pi. 27, 

 f. 20-26* ; Clyde, p. 42, pi. 5, f. 76) ; plate 24, fig. 672. 



Frustule elliptic. Valve angularly plicate round a line uniting the two 

 apices, so that when viewed from the apex it appears to consist of two laminae 

 placed at an angle of 6o. Valve with lunate outline, arcuate near the 

 exterior, with the interior margin straight and apices acute. Axial area 

 moderately broad on the dorsal side of the raphe. Ventral portion of the 

 valve linear, narrow, wuhout striae and longitudinal line. Dorsal side with 

 transverse striae robust, especially at the external portion. Striae 10 in r 

 c.d.m., coarsely punctate ; 12 dots in 1 c.d.m. Sutural zone very narrow. 

 Length of frustule 4 to 8 c.d.m. ; breadth, 1-5 to 2 c.d.m. 



Marine. Coasts of Norway. 



There is no known species analogous to A. dubia (Cleve). 



A. Pusio Cleve (Syn. Nav. Diat., p. 102, pi. 3, f. 40*) ; plate 35, 

 fig. 906. 



Frustule broadly elliptic with truncate apices. Raphe strongly bi-arcuate. 



Central nodule large. Axial and central areas indistinct. Ventral and 



dorsal sides with robust striae, about 14 in 1 c.d.m , not interrupted and 



not distinctly punctate 



Marine and brackish water. Coasts of Sweden (CI. and Moll. Diat., No. 157). 



A. arenicola Grun. (in CI. and Moll. Diat., No. 310, sub 

 A marina var arenico/a ; Cleve Syn. Nav. Diat., pi. 4, f. 19-20), plate 35, 

 fig. 907. 



