A6 
consider this as somewhat belonging to the Nautilus, [ 
therefore retain it in that genus at present, rather than 
go farther, beyond the limits of general knowledge. 
Nautilus calcar of Fichtel is quoted by Montfort, but it 
appears certainly to differ from either. _ I am sorry not to 
be able to find the siphuncle, but I suspect it is at the 
outer extremity. In all my specimens, which is seldomer 
the case in Nautili than in Ammonites, it was obscure: 
one had a little break where I expected it, but I could 
not say it was there :---it must therefore be left for further 
research. 
