436 Miscellaneous. 
MISCELLANEOUS. 
Ctenodus cristatus. 
To the Editors of the Annals and Magazine of Natural History. 
Leeds, May 3, 1876. 
GENTLEMEN,—I am very willing to be corrected by Mr. Atthey ; 
and this letter is to be regarded as in the main a request for 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 upper 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- 
tutus and C. tuberculatus 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. 
Tf Mr. Atthey will assure us that he can substantiate by indispu- 
table specimens the restoration, Nat. Hist. Trans. N. & D. vol. iv. 
t. xiv., 1 am prepared to accept his statement, notwithstanding its 
prima facie improbability. Your obedient servant, 
L. C. Mratt. 
Observations on the Period of the Extinction of the ancient Fauna of 
the Island of Rodriguez. By M. Atrn. Mitne-Epwarps. 
The imperfect knowledge we possess of the ancient fauna of the 
island of Rodriguez, and the unexpected facts discovered by the 
paleontological 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 1691 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 paleontological 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 by Leguat, and of which the species have entirely 
disappeared. But at what period did this extinction take place ? 
and to what cause was it due? ‘To resolve these questions we had 
no certain guide. We are now acquainted with another document 
