ill!Ill

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
from 16 to 18 in 1 c.d.m. at the
rostrate-capitate; striae fine, punctate,
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
Marine. Coasts of Norway.
to 2 c.d.m.
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.