SPECIMENS FROM HUGH MILLER. 475 



which in the Asterolepis, as in the sturgeon, 

 consisted each of a single plate. In both the 

 exterior surface of the buckler and of the 

 operculum the tubercles are a good deal en- 

 veloped in the stone, which is of a consistency 

 too hard to be removed without injuring what 

 it overlies; but you will find them in the 

 smaller cast which accompanies the others, 

 and which, as shown by the thickness of the 

 plate in the original, indicates their size and 

 form in a large individual, very characteristic- 

 ally shown. So coral-like is their aspect, that 

 if it was from such a cast, not a fossil (which 

 would, of course, exhibit the peculiarities of 

 the bone), that Lamarck founded his genus 

 Monticularia, I think his apology for the error 

 might almost be maintained as good. I am 

 sorry I cannot venture on taking casts from 

 some of my other specimens ; but they are 

 exceedingly fragile, and as they are still with- 

 out duplicates I am afraid to hazard them. 

 Since publishing my little volume I have got 

 several new plates of Asterolepis, a broad 

 palatal plate, covered with tubercles, consider- 

 ably larger than those of the creature's ex- 

 ternal surface, a key - stone shaped plate, 

 placed, when in situ, in advance of the little 

 plate between the eyes, which form the head 



