24 Oliver and Salisbury . — On the Structure and 
origin and approximate plane. Those marked with an asterisk are figured 
in the plates. 
U.C.L., R. 140 a*, b*, c, d* 
Series of four transverse sections 
Langendreer, Westphalia 
J. 3 * 
Oblique through pollen-chamber 
Rheinpreussen (nr. 
Duisburg) 
J- 4 
Tangential 
yy 
J. 5 
Oblique transverse 
» 
yy 
J. 6* 
Oblique longitudinal 
yy 
yy 
J. 9* 
Oblique through pollen-chamber 
yy 
yy 
J. 10 
Tangential 
yy 
yy 
J. 11 
Oblique through middle 
yy 
yy 
J. 12* 
Longitudinal, passing through micropyle 
yy 
yy 
J. 13 
Oblique transverse 
yy 
yy 
J- 14 
Tangential 
yy 
y y 
J- 15 
Oblique transverse 
yy 
yy 
J. 16 
Oblique transverse 
yy 
yy 
U.C.L., Q. 18* 
Oblique transverse near base 
Shore, Littleborough, 1904 
U.C.L., R. 141 
Very imperfect transverse 
Dulesgate 
U .C.L., R. 142 a and b 
Imperfect transverse 
Shore, Littleborough, 1910 
The specimens marked ‘ J .’ are in the collection of Dr. J. W. Jongmans 
of Leiden. (The numbers of these specimens are provisional.) 
The approximate plane of all the more important sections has been 
plotted on the longitudinal and transverse diagrams in Text-fig. 8. 
2. General Features. 
In the fundamental characters both of external form and internal 
organization the present species agrees closely with Conostoma oblongum. 
Like that species it was a straight, angled seed, roughly bullet-shaped, with 
a tapering apex and gradual insertion. 
Internally there was an extensive plinth which had a comparatively 
small globular lagenostome at its apex. But whilst in essentials it was 
an undoubted Conostoma it possessed a very characteristic individuality of 
its own. 
Superficially, the most striking feature was its extreme length as com- 
pared with its width ; this latter was the same as in the other species, but it 
attained a maximum length of 7 mm. The main body of the seed was 
eight-angled, the angles bearing externally ribs which were alternately large 
and small ; the former in the middle region being twice as prominent as the 
latter (o*n mm. and 0-05 mm.). 
The base of the seed tapered gradually to a thick stalk bearing eight 
wings, the lower extensions of the ribs. At the summit the surface curved 
inwards almost abruptly, terminating in a short conical apex pierced by the 
micropyle (Text-fig. 9). At the base of this tube the smaller ribs die out, 
but the four larger persist as wing-like expansions around the micropylar 
region, beyond the orifice of which outer margins are produced as free 
points. At the apex of the seed was an almost hemispherical depression 
about 0-4 mm. deep, bounded by the internal edges of the wings (Text* 
