24 BRITISH FOSSIL CORALS. 



2. Paracyathus Caryophyllus. Tab. IV, figs. 2, 2 a, 2 b, 2 c, 2d, 2 e. 



Turbinolia caryophyllus, Lamarck. Hist, des Anim. sans Verteb., t. ii, p. 232, 1816; 



2d edit., p. 362. 



— — Deslongchamps. Encyclop. method., Zooph., p. 761, 1824. 



— — Lamarck. Tableau encyclop. ei method, des trois Regnes, 



t. iii, p. 483, fig. 3, 1827. 



— — Def ranee. Diet, des Sc. Nat., t. lvi, p. 92, 1828. 

 Paracyathus caryophyllus, Milne Edwards and J. Haime. Monogr. des Turbinolides, 



Ann. des Sc. Nat., 3 me serie, vol. ix, p. 322, 1848. 



Corallum turbinate, elongated, almost cylindrical in the tallest specimens, usually 

 straight, or very slightly curved, and adhering by a moderately developed basis. Costa 

 well marked, distinct from top to bottom, nearly equal, rather narrow, not much more 

 prominent towards the calice than near the basis, separated by broad, deep furrows, and 

 covered with small granulations, which exist also in the intercostal furrows (fig. 2 b). 

 Calice circular ; fossula not very deep. Columella concave, delicately papillose, and not 

 distinctly separated from the pali (fig. 2g). Septa forming four cycla, the last of which is 

 wanting in half of one or two systems ; closely set, not very exsert, thin, strongly granu- 

 lated laterally, and rather unequal in accordance with their relative age ; the primary and 

 secondary ones rather thick externally. Pali very thin, rather tall, lobated, with the inner 

 edge oblique, and gradually larger as the septa to which they correspond are younger. 

 Height, varying from five to eight lines ; diameter of the calice, three or four lines ; depth 

 of the fossula, one line and a half. 



This fossil is in general found in a bad state of preservation, being much worn away, 

 with its basis obtuse, its wall almost entirely destroyed, and the visceral chamber tilled 

 with a carboniferous substance, the black tint of which contrasts with the white colour of 

 the septa. Lamarck, who had only seen specimens in this state, was thus led to suppose 

 that the corallum was free, and to consider it as appertaining to the genus Turbinolia. 

 But, through the kindness of Mr. Bowerbank and Mr. Dixon, we have been enabled to 

 examine a great number of specimens, some of which presented a complete calice, well- 

 preserved costae, and a basis that had evidently been adherent, so that no uncertainty 

 could remain as to their belonging to our genus Paracyathus. This species differs from 

 most other nearly allied species by the thinness of the pali, a character which is to be seen 

 only in one other species ; the Paracyathus brevis, from which T. caryophyllus is easily 

 distinguished, by its septa being also much thinner. The number of the septa can equally 

 serve as a character, for in Paracyathus Stokesii, P. Desnoyersii, and P. procumbens, there 

 is a cyclum more than in the species here described. 



Paracyathus caryophyllus is a very common fossil in the London Clay at the Isle of 

 Sheppy ; specimens of it are preserved in the collections belonging to the Geological 

 Society of London, Mr. Bowerbank, Mr. Dixon, Mr. Frederick Edwards, the Museum of 

 Paris, and M. Milne Edwards. 



