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5
ASTEROLAMPRE^E.
W. insignis Panl., fossil at Ananino, Russia (fig. 243), drawn from my
photograph of Dr. Pantocsek's specimen.
This genus appears to me to be very closely approximate to the preceding.
It will be necessary to examine a larger number of quite perfect valves to
identify or differentiate the two genera definitely.
TRIBE XXIV. ASTEROLAMPRE/E.
Table of Genera.
"Valve furnished with strong internal costae, united to one another at the centre and
sides by a robust internal lamina, centre hyaline
( Valves hyaline, angular or circular, without costas or straight rays not enlarged
near the margin or near the centre, and not touching the margin
2^
o
Arachnoidiscus.
. Liostephania.
fDisc radiated, punctate, cellular or granular, with centre granular, not
stellate, with marginal portion divided into numerous compartments by
enlarged costae in the form of spokes of a wheel
Gyroptychus.
o -i
a
f Valves inflated, hyaline or punctate, with centre sometimes stellate,
,-
I I I I
rays linear, more or less bifurcated and somewhat irregular ; interspaces
hyaline or with flexed or sinuous lines
be
a
o
f Valves hyaline, divided by simple rays ; centre hyaline or granu-
lar, reticulate, or finely punctate .
o .
c P.
IT,
,0
o B
O
O
rt
f Rays simple, straight, never reaching to the centre ;
puncta more or less large and scattered
I Valve
Cladogramma.
Mastogonia.
Stietodiscus.
Rays irregular both as to length and division, often
divided dichotomously ; valves with cells small, uniform
throughout the surface . . . Radiopalma.
V
a o
g as
m k 8
ST
2 a
3 'o
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