78 BRITISH FOSSIL CORALS. 



the other above-mentioned differences do not appear to have sufficient value, and the 

 genera Lobocania, Conocania, Adelocania, Tremoccenia, CryptoccBnia, Dendrocoinia, Aplo- 

 sastrea, Octocania, Decaccenia, and Pseudocania of M. d'Orhigny, may still remain united 

 in a single generical group, under the old name of Stylina. This genus belongs exclusively 

 to the secondary period, and most of its representatives are found in strata of the Jurassic 

 formation. 



Stylina tuhulifera, having 10 principal septa, belongs to the genus Becaccenia in M. 

 D'Orbigny's method of classification ; and this peculiarity, which is met with but in a few 

 other species of Stylina, distinguishes it from all those in which the calice is divided into 

 6, 8, or 12 equal parts. All the Stylina which have this number of principal septa are 

 very nearly allied to each other, and most of those which are at present considered as being 

 specifically distinct, may very likely prove to be nothing more than varieties of one species ; 

 but we have not been able to examine a sufficient number of well-preserved specimens in 

 order to decide this question. Thus, Stylina lobata^ may perhaps be a young specimen of 

 8. tuhulifera, with short corallites, and very prominent, widely-set calices ; and Stylina 

 octonis^ only differs from the above-described species by the calices being more closely set, 

 somewhat unequal in size, and about \\ lines in diameter. The specimens on which these 

 two species were established are both in a very bad state of preservation. S. tulmlifera also 

 resembles very much another fossil which was found in the Great Oolite near Bath, and 

 will be described in a subsequent chapter of this Monograph, under the name of S. Ploti ; 

 the latter, however, has a smaller columella, thinner septa, and less prominent calices. The 

 fossil coral mentioned by M. D'Orbigny, under the name of Decacania magnijiccc' is more 

 easily distinguished from S. tuhulifera, and in some calices shows only 8 large septa instead 

 of 10, as is the case in most. It is a slightly convex mass, with calices of unequal size, 

 but slightly prominent, and of 2^ lines diameter ; the costse are nearly equal, and delicate ; 

 three very small but well-characterised septa exist between each of the principal septa. 

 This new species appears to have been found in the Coral Rag of Chatel Censoir and of 

 Wagnon, Ardennes. We must also add that, by its general aspect, S. tuhulifera resembles 

 very much S. tuhidosa^ described by Goldfuss ; and in the figure given by that able 

 Palaeontologist, this latter species is represented as having 10 principal septa ; but that 

 is not in reality the case, for in the original specimen belonging to the Poppelsdorf 

 Museum, at Bonn, we ascertained the existence of 12 of these septa. 



' Explanaria lobata, Goldfuss, Petref. Germ., tab. 38, fig. 5. 



^ Pseudocceida octonis, D'Orbigny, Prodrome, vol. ii, p. 34. 



"^ Prod, de Paleontol., vol. ii, p. 33. 



* Astrca tuhulosa, Goldfuss, Petref. Germ., vol. i, tab. xxxviii, fig. 15. 



