206 BRITISH FOSSIL CORALS. 



Astrea emarcida, Fischer, Oryct. de Moscou, p. 154, pi. xxxi, fig. 5, 1837. 



— pentagona (?), Ibid., p. 154. 



— mammillaris, Fischer, ibid., p. 154, pi. xxxi, figs. 2, 3. 



Cyathophyllum expansum, Ibid., p. 155, pi. 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, b, c, 1845. 

 Cyathophyllum astrea, Brown, Ind. Palseont., p. 367, 1848. 



Strombodes conaxis, M'Coy, Ann. and Mag. of Nat. Hist., 2d ser., vol. iii, p. 10, 1849. 

 Lithostrotion mamillare, UOrbigny, Prodr. de Pal., vol. i, p. 159, 1850. 

 Lonsdalia floriformis, Milne Edwards and Jules Haime, Pol. Foss. des Terr. Palaeoz., 



p. 458, 1851. 

 Strombodes conaxis, M'Coy, Brit. Palaeoz. Foss., p. 102, pi. 3 b, fig. 4, 1851. 

 — floriforme, Ibid., 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. Twenty-four principal septa, 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 laminae 

 pass through the concentric laminae 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, &c. 



The generic division, designated here under the name of Lonsdaleia, has been considered 

 by Mr. Lonsdale and by many of our contemporaries as being the genus Lithostrotion, 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, Lithostrotion, applies to the Lithostrotion of 



