22 BRITISH FOSSIL COEALS. 



The genus Leptocyathus, which we have established for this fossil, is nearly allied to 

 Trochocyathus, but differs from it by its subdiscoidal form, the absence of all sign of 

 adhesion at the basis, and the existence of pali corresponding to all the septa. The genus 

 Ecmesus of Philippi 1 appears to present most of the same characters, but, as far as we can 

 judge by the very short description, and by the rough figure given by that author, the 

 calice appears to be eccentric, a mode of structure which is quite exceptional, and 

 very remarkable. 



The fossil Coral from the environs of Biaritz, mentioned by Viscount d'Archiac 2 

 under the name of Turbinolia atalayensis, belongs probably to the same generical division 

 as our Leptocyathus elegans, but differs from it by its large size, by the existence of a fifth 

 cyclum of septa, and by the smooth surface of the central portion of its wall. 



Leptocyathus elegans was found in the London Clay, at Haverstock Hill, by Mr. 

 Frederick Edwards, who obligingly communicated to us the only specimen that has as yet 

 been seen. 



2. Genus Trochocyathus (p. xiv). 

 Trochocyathus sinuosus. 



Turbinolia turbinata (pars), Lamarck, Hist, des An. sans Vert., t. ii, p. 231, 1816. 



— .... Parkinson, Organic Remains, vol. ii, tab. iv, fig. 11, 1820. 



— sinuosa, Alex. Brongniart, Mem. sur les Terr, du Vicentin, p. 83, pi. vi, 



fig. 17, 1823. 



— — Bronn, Syst. des Urweltlichen Pflanz., tab. v, fig. 12, 1825. (Bad 



figure.) 



— dubia, Defrance, Diet, des Sc. Nat., vol. lvi, p. 92, 1828. 



— sinuosa, Bronn, Lethea Geognostica, vol. ii, p. 897, 1838. 



_ _ Leymerie, Mem. de la Soc. Geol. de France, 2 me serie, pi. xiii, 



figs. 7, 8, 1845. 



— — Michelin, Icon. Zooph., p. 270, pi. lxiii, fig. 1, 1846. 

 Trochocyathus sinuosus, Milne Edwards and J. Haime, Ann. des Sc. Nat., 3 m ' serie, 



vol. ix, p. 314, 1848. 



We have not met with this fossil in any collection of the British Corals, but Parkinson 

 has figured it in a very recognisable way, and mentions it as having been found in the 

 Isle of Sheppy; we must therefore recall its specific characters in this monograph, 

 although we deem it advisable not to have it figured from a foreign specimen. 



Corallum subturbinate, rather compressed, and having its inferior extremity slightly 

 curved in the direction of the small axis of the calice. Costa distinct from the basis, very 

 narrow, numerous, closely set, simple, unequal, delicately granulated, and projecting very 

 little. Calice oval, and contracted in the middle, so as to assume the form of an 8. 



1 Neues Jahrb. fur Mineral. Geol., vol. ix, p. 665, tab. xi, fig. B 1, 1841. 



2 Bulletin de la Soc. Geol. de France, 2 me serie, vol. ii, p. 1010, 1847. 



