24 BRITISH FOSSIL CORALS. 
2. Paracyatuus Caryopnyiivus. Tab. IV, figs. 2, 2a, 26, 2c, 2d, 2e. 
TOURBINOLIA CARYOPHYLLUS, Lamarck. Hist. des Anim. sans Vertéb., t. ii, p. 232, 1816; 
2d edit., p. 362. 
— — Deslongchamps. Encyclop. méthod., Zooph., p. 761, 1824. 
— — Lamarck. Tableau encyclop. et méthod. des trois Régnes, 
t. iii, p. 483, fig. 3, 1827. 
— _— Defrance. Dict. des Sc. Nat., t. lvi, p. 92, 1828. 
PARACYATHUS CARYOPHYLLUS, Milne Edwards and J. Haime. Monogr. des Turbinolides, 
Ann. des Sc. Nat., 3™° série, 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. Coste 
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 4). 
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 im accordance with their relative age; the primary and 
secondary ones rather thick externally. Padi 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 filled 
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 Zwrdinolia. 
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 coste, and a basis that had evidently been adherent, so that no uncertainty 
could remain as to their belonging to our genus Paracyathus. his 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 7. caryophyllus is easily 
distinguished, by its septa bemg also much thinner. ‘The number of the septa can equally 
serve as a character, for in Paracyathus Stokesii, P. Desnoyersit, and P. procumbens, there 
is a cyclum more than in the species here described. 
Paracyathus caryophyllus is «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. 
