206 BRITISH FOSSIL CORALS. 
ASTREA EMARCIDA, Fischer, Oryct. de Moscou, p. 154, pl. xxxi, fig. 5, 1837. 
—  pENTAGONA (?), Ibid., p. 154. 
— MAMMILLARIS, Fischer, ibid., p. 154, pl. xxxi, figs. 2, 3. 
CYATHOPHYLLUM EXxPaNsuM, Ibid., p. 155, pl. xxxi, fig. 1, 1837. (Named Astrea expansa, 
in the first edition, 1830.) 
LITHOSTROTION MAMILLARE, and ASTROIDES, Lonsdale, in Murch., Vern., Keys., Russ. and 
Ur., vol. i, pp. 606, 607, figs. a, 6, c, 1845. 
CYATHOPHYLLUM ASTREA, Bronn, Ind. Palont., p. 367, 1848. 
SrromBopes conaxis, M‘Coy, Ann. and Mag. of Nat. Hist., 2d ser., vol. iii, p. 10, 1849. 
LITHOSTROTION MAMILLARE, D’ Orbigny, Prodr. de Pal., vol. i, p. 159, 1850. 
LonspaLia FLORTFORMIS, Milne Edwards and Jules Haime, Pol. Foss. des Terr. Palzeoz., 
p- 458, 1851. 
STROMBODES conaxis, M‘Coy, Brit. Palzoz. Foss., p. 102, pl. 38, fig. 4, 1851. 
— FLORIFORME, Jdid., p. 103. 
Corallum astreiform. Corallites prismatic, very unequal in size, and separated by 
well-developed exothecal walls. Calices rather deep. Columella stout, very prominent, 
compressed at its end, which assumes the form of a small crest, and presents, on its lateral 
sides, ascendant curved ridges. '['wenty-four principal seta, which are thin, narrow ; form 
in general, a slight annular protuberance round the central fossula, and alternate with an 
equal number of smaller septa. The costal prolongation of the septal radii pretty well 
marked on the exterior zone. Diagonal of the large corallites 8 or 10 lines, sometimes 
half as much more ; diameter of the inner walls from 3 to 5 lines. 
A vertical section shows that the interseptal dissepiments are very closely set, (about 
half a line apart,) and almost horizontal, or sloping slightly upwards towards the columella ; 
the inner walls but little developed, and the vesicles of the exterior zone very unequal in 
size and very oblique inwards. A horizontal section shows that four or five of these 
vesicles are placed between the outer and inner walls, and that the regular radiate laminze 
pass through the concentric laminz of the columella, which is dense in the axis of the 
corallite. 
Found at Bristol, Lilleshall, Mold, Oswestry, Whitehaven, Maryport, (Cumberland,) 
according to Professor Phillips, at Bolland, and according to Professor M‘Coy, at Bakewell, 
in Derbyshire. It is also met with in the carboniferous formation in Russia. Specimens 
are in the collections of the Geological Society, of the Museum of Practical Geology, of 
the Bristol and Cambridge Museums, of Mr. Bowerbank, of Professor Phillips, of the 
Paris Museum, We. 
The generic division, designated here under the name of Zonsdaleia, has been considered 
by Mr. Lonsdale and by many of our contemporaries as being the genus Zzthostrotion, of 
Fleming; but the figure in Llwyd’s work, quoted by that geologist, can admit of no 
uncertainty as to the real signification of the latter group, which, as we have already said, 
was evidently intended to receive the coral described above under that name. Professor 
M‘Coy, who does not adopt Fleming’s genus, Zithostrotion, applies to the Lithostrotion of 
