A monograph of the British fossil corals - kreidefossilien.de
A monograph of the British fossil corals - kreidefossilien.de
A monograph of the British fossil corals - kreidefossilien.de
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68 BRITISH FOSSIL CORALS.<br />
only by cliaracters <strong>of</strong> secondary value, which agree, however, very well with those <strong>of</strong> <strong>the</strong><br />
o<strong>the</strong>r Corals belonging to <strong>the</strong> same generical division.<br />
Septa forming four complete cycla<br />
exsert, thick exteriorly, but thin inwardly, and presenting but few granulations on <strong>the</strong>ir<br />
lateral siu-faces. Those <strong>of</strong> <strong>the</strong> second cyclum almost as large as <strong>the</strong> primary ones ; <strong>the</strong><br />
tertiary ones but little <strong>de</strong>veloped, although <strong>the</strong>y correspond to large costse, and not as tall<br />
as those <strong>of</strong> <strong>the</strong> last cyclum, which are grouped very closely on each si<strong>de</strong> <strong>of</strong> <strong>the</strong> primary and<br />
secondary ones. Height <strong>of</strong> <strong>the</strong> coraUum, one inch two or three lines ;<br />
great diameter <strong>of</strong><br />
<strong>the</strong> calice,<br />
six or seven lines.<br />
The genus Bathycyatlms contains two o<strong>the</strong>r species, which are both recent : B. CMlensis^<br />
and B. Indicus,~ which differ from B. Soioerbp in having an additional cyclum <strong>of</strong> septa,<br />
<strong>the</strong> calice arched, and <strong>the</strong> costse more <strong>de</strong>veloped near <strong>the</strong> basis. We have seen but two<br />
specimens <strong>of</strong> this <strong>fossil</strong> ; one, belonging to <strong>the</strong> collection <strong>of</strong> Mr. D. Sharpe, is catalogued<br />
as having been found in <strong>the</strong> Gault near Folkstone ; <strong>the</strong> second, belonging to <strong>the</strong> museum<br />
<strong>of</strong> <strong>the</strong> Geological Society, is referred with doubt to <strong>the</strong> upper greensand <strong>of</strong> Kidge, in<br />
Wiltshire.<br />
Family ASTREIDtE (p.<br />
xxiii).<br />
Tribe EUSMILINiE (p.<br />
xxiii).<br />
1. Genus Trochosmilia (p. xxiv).<br />
Trochosmilia sulcata. Tab. XI, fig. 6, 6 «, 6 b.<br />
Corallum simple, tm-binate, straight, tall, much compressed, subpedicellate, and appearing<br />
to be free. Wall presenting on each si<strong>de</strong> two <strong>de</strong>ep longitudinal furrows. Costce<br />
distinct from <strong>the</strong> basis, slightly prominent, closely set, and unequal, especially towards <strong>the</strong>ir<br />
upper end. Calice elliptical, sublobulated, and slightly arched ; its long and short axis in<br />
<strong>the</strong> proportion <strong>of</strong> 100:200. Fossula very narrow, elongated, and not very <strong>de</strong>ep. No<br />
columella.<br />
Septa forming four cycla or more, ra<strong>the</strong>r unequal, closely set, thin, and slightly<br />
exsert. Dissepiments not numerous. Height <strong>of</strong> <strong>the</strong> corallum, nearly one inch ; diameter<br />
<strong>of</strong> <strong>the</strong> calice, six or seven lines by three ;<br />
<strong>de</strong>pth <strong>of</strong> <strong>the</strong> fossula, two Unes and a half.<br />
We have seen but one specimen <strong>of</strong> this <strong>fossil</strong>, which, although somewhat wea<strong>the</strong>r-worn,<br />
appeared sufficiently distinct from all o<strong>the</strong>r species to authorise us in giving it a peculiar<br />
specific name. It differs from Trochosmilia dichjmci' by its cahce being straight, and not<br />
^ See our Monograph <strong>of</strong> TurbinoliJse, tab. ix, fig. 5.<br />
- Loc. cit., tab. ix, fig. 4.<br />
^ Turbinolia didyma, Goldfuss, Petref. Germ., vol. i, tab. xv, fig. 11.