Mr. W. Lonsdale on the Genus Lithostrotion. 459 



propriety be assumed to be the fossil of that authority; and 

 three of them (Nos. 2, 3 and 4) have been so identified. It 

 would nevertheless, in the present state of knowledge, and the 

 demand for detailed information, be altogether unjustifiable to 

 refer any one of the series positively to Lhwyd's coral ; and the 

 author conceives that the subsequent investigations have fully 

 supported the doubts which he entertained, when the Russian 

 collection was under examination, as well as the correctness of 

 the generic determinations then proposed. 



In resuming the observations on Lithostrotion, it is necessary 

 to state, that Prof. M'Coy in January 1849* considered the ge- 

 nus, as defined by the compiler of these memoranda, to be equi- 

 valent to the Strombodes of Schweigger f, adopting that natu- 

 ralist's first division of the genus (Coni e centro proliferi) as its 

 limits. It is not known whether the opinion is maintained ; 

 nevertheless should it be, the author feels assured that a recon- 

 sideration of the subject will afford grounds for doubting whe- 

 ther the known structures of Lithostrotion can exist in Fougt's J 

 Madrepora composita, confining the attention to figure 11 and 

 diagram no. 4, to which alone Schweigger refers. The next 

 known notice of Lithostrotion occurs in the Introduction to M. 

 Milne-Edwards and M. Jules Hairnets § first memoir on ( British 

 Fossil Corals' {op. cit. infra, p. lxxii.). The genus is stated to 

 consist of the Lithostrotion of Fleming in part ; and the charac- 

 ters expressly mentioned are — " columella formed by a fasciculus 

 of twisted bands, and the septa " (lamellse) " subvesicular exte- 

 riorly and joining the columella along their inner edge." Lith. 

 floriforme of Fleming is also given as the " typical species ; but 

 it is not known to what genus Lith. striatum was referred when 

 the ' Introduction \ was written. In the portions of volume v. 

 of the ' Archives du Museum d'Histoire Naturelle ' published 

 during the present year (1851) is a " Monographic des Poly- 

 piers Fossiles des Terrains Palseozoiques," also by M. Milne- 

 Edwards and M. J. Haime ; but Lithostrotion has different ge- 

 neric characters assigned to it ; and in the General Classification 

 of corals by which the monograph is preceded (p. 172), L. stri- 

 atum, Fleming, is the " example " whereby the genus may be 

 identified. The following are the generic equivalents and cha- 

 racters given in the body of the work (p. 432) : — 



Lithostrotion (pars), Fleming; Lithodendron, Phillips (non 



* Ann. and Mag. Nat. Hist. 2nd Series, vol. iii. p. 10, January 1849. 



f Beobachtungen auf Naturhistorischen Reisen. Systematic Table, 6, 

 1819. 



% Dissertatio de Coralliis Balticis, 1745, apud Amcenitates Academicas, 

 vol. i. p. 198, illustrative plate, fig. 11, and diagram no. 4. 



§ Memoirs of the Palseontographical Society, first volume for 1 850. 



