H7 
ferent directions in which the sections have been formed, the various 
structure of the several parts of these fossils. 
I am not, of my own knowledge, able to speak of the existence of 
these fossils in Great Britain. They appear, however, from Lhwydd’s 
catalogue, to be by no means rare, in different parts of Gloucester- 
shire, Oxfordshire, Northamptonshire, &c. 
It is exceedingly gratifying to me, to be able, through the kindness 
of Mr. Meade, to place before you a representation of a beautiful mi- 
nute orthoceratite, brought by him from the Appennines, near Sienna. 
Plate VIII. Fig. 16, is the fossil of its natural size ; and Fig. Vj is the 
representation of the same fossil, magnified by a single lens, for the 
purpose of obtaining a more distinct view of its structure. 
Colonel Montague, alluding to a recent, minute, straight, chambered 
shell, varying in some respects from N. costatus, Linn, gives the fol- 
lowing description of this fossil, which I take the liberty of introducing, 
not merely on account of its perspicuity and correctness, but because 
I could not myself have subjected a sufficient number to real inspection, 
without trespassing further than I wished on Mr. Meade’s kindness. 
“ A most elegant shell of this kind is found fossil upon the Appen- 
nines, near Sienna, several of which we have been favoured with by 
Mr. Meade and Mr. Higginson. These vary a little ; but the most 
perfect are an inch in length, completely cylindric, except at the last 
joint, which is rather larger, and terminates conically, ending in a 
small protuberance, nearly half as long as the joint to which it belongs ; 
the anterior end of those which appear perfect, is a little contracted 
round, and smooth, or projecting beyond the ribs ; in the centre is 
placed the aperture or syphon, whose margin is finely crenated. 
“ They vary also as much in the number of chambers as in that of 
the ribs ; possessing from ten to fifteen of the former, and from nine 
to twelve of the latter ; the joints are not much raised, but usually 
two or three at the anterior end more than the rest. The shell is ex- 
tremely thick in proportion ; and we found, by dividing several down 
