436 Misci'Ua/ii'uus, 



MISCELLANEOUS. 

 Ctenodus cnstatus. 



I'o the Editors of the Annals and Mayazlne of Natural History. 



Leeds, May 3, 1875, 

 Gentlemen, — I am very willing to be corrected by Mr. Atthey ; 

 and this letter is to be regarded us iu the maiu a request lor further 

 information. 



In Messrs. Hancock and Atthey's original paper (Nat. Hist. 

 Trans. N. & D. vol. iii. p. 61), and again in Mr. Atthey's note 

 (' Annals,' May 1875), the ^qyper surface of the palatal tooth of 

 Ctenodus cristatus is said to be concave. I have always understood 

 this to be their proposition, and controverted it by stating that in 

 the example now in the Leeds Museum the lower surface is concave. 

 No specimen which I have seen shows the upper surface of the 

 tooth ; nor have I hitherto mentioned it. If the upper surface be 

 concave, the lower or exposed surface would be convex, unless it be 

 contended that the tooth has greatly thickened edges, which is not 

 actually the case. Is it possible that Mr. Atthey has mistaken the 

 upper for the under surface ? If so, I may well have failed to 

 catch his meaning. 



I have never been satisfied that the distinction between C. cris- 

 tatus and C. tuherculatus was well founded ; but I readily admit 

 that I ought either to have stated this explicitly, or to have cited 

 Messrs. Hancock and Atthey's statement in their own language. 

 Criticism of proposed species, however, was no part of my plan. 



If Mr. Atthey will assure us that he can substantiate by indispu- 

 table specimens the restoration, Nat. Hist. Trans. N. tfe D. vol. iv. 

 t. xiv., I am jirepared to accept his statement, notwithstanding its 

 primd facie improbability. Your obedient servant, 



L. C. MlALL. 



Observations on the Period of the Extinction of the ancient Fauna of 

 the Islaml of Hodriyuez. By M. Alph. Milne-Edwards. 



The imperfect knowledge we possess of the ancient fauna of the 

 island of Rodriguez, and the unexpected facts discovered by the 

 palaeontological study of the bones collected from the caves there, 

 give real importance to all the authentic information we can find in 

 the accounts of the old travellers on the productions of that island. 

 Francois Leguat, who staid at Rodriguez from lO'Jl to 1693, and 

 published some very careful observations on all he had seen there, 

 described its plants and animals. Most of his assertions have been 

 corroborated by the palaiontological discoveries recently made ; and, 

 in several memoirs which I have had the honour to present to the 

 Academy, I have made known the zoological characters of some 

 birds mentioned l)y Leguat, and of which the species have entirelj' 

 disapi)eared. But at what period did <his extinction take place? 

 find to what cause was it due? To resolve these questions we had 

 no certain guidf. We arc now acquainted with another document 



