CORALS FROM THE CORAL RAG. 87 



nuda} wliicli is very much like T. irichotoma, by its general aspect, has also thinner and 

 more numerous septa. T. ramose^ may also be distinguished from T. annidaris by the 

 regular form and small size of its calices. T. (jregarid' differs still more from the prece- 

 ding species by the corallites remaining in general grouped in fasciculi to a considerable 

 distance from the parent calice, on which they were formed by fissiparous generation, a 

 mode of arrangement which we have not met with in other corals of the same genus. 



M. D'Orbigny has recently given the name of Lasmosmilia^ to a certain number of 

 fossil corals, which appear to us to be species of Thecosmilia that have been accidentally 

 deprived of their epitheca. The genus Amblophi/llia of the same author'^ is founded 

 on the existence of a rudimentary epitheca, and is probably composed only of speci- 

 mens of the same genus less completely weatherworn. If the different species men- 

 tioned under these two generical names were well characterised, it would be necessary 

 for us to compare them with the British species described here above; but that is far 

 from being the case. 



Genus Rhabdophyllia.^ 



Rhabdophyllia Phillipsi. Tab. XV, figs. 3, '^a, Sd, '3c. 



Caryophyllia, Phillips, lUustr. of the Geol. of Yorkshire, vol. i, p. 12G, 1829. 

 LiTHODENDRON Edwardsii, M'Coij, Ann. and Mag. of Nat. Hist., s. 2, vol. ii, p. 41 9, 1848; 



(but not Lit.hodendvon Edwardsii oi Michelin, as supposed by 



that author.) 

 Rhabdophyllia Phillipsi, Milne Edwards and J. Haime, Monogr. des Polyp. Palseoz., &c., 



loc. cit., p. 83, 1851. 



Corallum composite, dendroid ; corallites tall, almost cylindrical ; slightly tumified at 

 short distances, and becoming larger and somewhat compressed where they dichotomise. 

 This division takes place frequently, and the newly formed branches diverge at an angle of 

 about 50°. Cost(B very distinct, rather thick, granulose, almost equally developed, closely 

 set, and often dichotomose (fig. 3«). The calices, when young, are regularly circular, as 

 may be inferred from the form of the corallum, but the terminal portion of the branches was 

 broken off in the specimens we have seen. A horizontal section, made at some distance 



1 D'Orbigny, Prod., t. i, p. 389. 2 ib., p. 291. 



^ Tab. xxviii, fig. 1. '' Note sur des Pol. Foss., p. 6. 



'^ Note sur des Pol. Foss., p. 8. Amhlophyllia riipellensis (D'Orbigny, Prod, de Pak'ont., vol. ii, p. 30,) 

 is a species established for a cast, which does not appear to us susceptible of being characterised. 



Ambloj)hjllia ohtusa (D'Orbigny, Op. cit., vol. i, p. 285,) is known only by a very young specimen, in 

 which the three calices are not yet become distinct, and present each about smiy septa belonging to three or 

 four different cycla, and delicately dentate on the edge ; but this species appears to differ from all others 

 previously described by the loosely set prominent radiate striae that cover the sides of the sepfa. 



<* Milne Edwards and J. Haime, Polyp. Foss. des Terr. Palseoz., &c., p. 83. 



