108 BRITISH POSSIL CORALS. 



did not deem it necessary to maintain the distinction between the two generical divisions 

 thus characterised. In om- Monograph of the Astreidse we, therefore, described the typical 

 species of Ci/athophora under the denomination of Stylina Bourgueti. But since the 

 publication of that work we have examined a greater number of specimens of this species 

 without ever finding in them any trace of a columella ; other species have shown the same 

 peculiarity ; we must consequently feel less confident in the justness of our former views 

 on the subject, and, till further data be procured, we do not feel authorised to abolish the 

 genus Cyathopliora. We have provisionally replaced it in our synopsis of the classification 

 of corals lately published,^ and we include in it four species : C. Bourgueti, already men- 

 tioned, C. monticularia," C. Pratti^ and C. Luciensis:^ 



The latter is easily distinguished from the three others by the small size of its calices, 

 and its septa being less numerous. 



The genus Cryptoccenia, to which M. D'Orbigny refers this fossil, is a subdivision of 

 the genus Stylina as delimitated in the system of classification adopted in this Monograph. 



2. Cyathophora Pratti. Tab. XXI, figs. 3, 3a. 



Corallum massive, very convex, and fixed by a broad basis. Calices unequally dis- 

 tant, quite circular, and not very prominent. Costa thin, straight, or slightly flexuous 

 where they joiu those of a neighbouring corallite, alternately more or less prominent, 

 but all nearly of the same breadth, and closely set. They belong to four cycla. Calicular 

 fossula not very deep. Septa very thin, broad, slightly granulated, very unequal in size, 

 and forming three well developed cycla, besides one rudimentary cyclum. Those of the 

 first cyclum do not extend quite to the centre of the calice, where a small vacant space is 

 visible in all the corallites that we have examined, and no trace of a styliform columella 

 could be discovered. Diameter of the calices two lines or more. 



We have seen only three specimens of this species, and all were in a bad state of 

 preservation ; two were communicated to us by Mr. Pratt, and had been found at Comb- 

 Down, near Bath ; the other forms part of the collection that Mr. Walton has had the 

 kindness to place at our disposal for description. 



Cyathophora Pratti differs from C. Lucicnsis by its calices being much larger and 

 multiseptate. In C. monticularia the septa are thicker, and in C. Bourgueti^ the septal 

 systems, instead of being uniformly developed, are always unequal, the septa of the fourth 

 cyclum existing only in four of these groups. 



1 See Milne Edwards and J. Ilaimc, Polyp. Foss. des Terr. Pakcoz., p. C'2. 



2 Cydoccenia monticularia, D'Orbigny, Prodr. de Pal., vol. ii, p. 204. 



3 Tab. x.xi, fig. 3. ^ Tab. xxx, fig. 9. 



^ Having examined in the Poppclsdorf Museum the typical specimen of tbe Astrea aheolata of 

 Goldfuss, we have ascertained that it is not, as we formerly supposed, specifically identical M'itli C. Bour- 

 ffucti. Tbe two species are quite distinct ; but Astrea aheolata does not differ from the Coral which we 



