130 BRITISH FOSSIL CORALS. 



compressed and oval. M. trochoides has more general resemblance to a certain number of 

 species of a somewhat conical form, which have five or six cycla of septa, such as M. dispart 

 M. temiilamellosa, &c. The first of these fossils, however, differs from it by having a less 

 regular form, a shallower fossula, and fewer septa; M. termilamellosd?' is shorter, its 

 epitheca does not extend so high, and its septa are thinner and curved inwardly; 

 M. Wrigldi^ has thicker and more equally developed septa ; J/. Lotharingd^ has its basis 

 arched and often inflated ; M. Goldfussiana^ is always adherent ; M. Gueranger^ has a 

 thicker but very incomplete epitheca ; and in M. Beaumonti' the septa are more numerous 

 and fluted laterally. 



2. MoNTLIVALTIA TENUILAMELLOSA. Tab. XXVI, figS. 11, 11«. 



Corallum subturbinate, short, broader than high, somewhat inflated, straight, or very 

 shghtly subpedicellate. Epitheca very thick, extending over only two thirds of the height 

 of the corallum, and presenting strong circular wrinkles. Calice circular or nearly so, and 

 slightly convex ; fossula oval and very deep. Septa very thin, terminated by a very 

 delicately denticulated edge, almost smooth laterally, and forming six complete cycla ; those 

 of the first three cycla almost equally developed ; many of them somewhat bent towards the 

 centre of the visceral chamber. Height one inch. Diameter two inches. 



This fossil was found in a bed of Fullers Earth at Dunkerton, and at English Batch, 

 by Mr. Walton. 



The general form of this coral renders it easy to be distinguished from most of the 

 species of the genus Montlivaltia ; those which it resembles most, are M. ponderosa,^ 

 M. brevissima,^ M. Waterhousei}^ and M. regularis^^ but the first of these fossils is much 

 more oblong, has a thin and almost smooth epitheca, reaching almost to the calicular 

 margin, and straight septa ; in the second the epitheca is also almost complete and smooth, 

 and there are only five cycla of septa ; in the last two the corallum has much the same in 

 form towards its basis, but becomes cylindrical higher up, and the septa are stronger and 

 more numerous. 



1 Tab. xiv, fig. 2. ^ Tab. xxvi, fig. 11. » Tab. xxvi, fig. 12. 



4 Milne Edwards and J. Ilaime, loc. cit., p. 294. * lb., loc. cit. 



6 lb., op. cit., p. 293. '^ lb., Ann. des Sc. Nat., s. 3, vol. xi, p. 243. 



8 Thecophyllia ponderosa, Milne Edwards and J. Haime, Ann. des Sc. Nat., s. 3, vol. xi, p. 242. 

 8 Milne Edwards and J. liairae, op. cit., vol. x, p. 293. ^° Tab. xxvii, fig. 7. 



11 D'Orbigny, Prod, de Paleont., vol. i, p. 349. 



