290 PROROSCIDIA. 
Mastodon giganteus, which now appear to complete the 
demonstration of the specific identity of the Mastodon 
longirostris, and Mastodon angustidens. 
Besides portions of jaws and numerous detached molar 
teeth, fragments of tusks have been discovered in the 
fluvio-marine crag, exhibiting the characteristic decus- 
sating curvilinear impressions of true ivory, and most 
probably belonging to the Mastodon angustidens, which 
continental fossils prove to have possessed two large tusks 
in the upper jaw, like the Mastodon giganteus of America 
(see fig. 102). ‘These tusks are less extensively, and less 
obliquely curved than the tusks of the Mammoth (fig. 85). 
Certain individuals of the Mastodon anqustidens, probably 
the males, have likewise been shewn by continental spe- 
cimens, to have had small straight tusks in the lower jaw, 
and I am able to add the testimony of a British fossil in 
proof of this correspondence between the Kuropean narrow- 
toothed Mastodon, and the Mastodon giganteus of North 
America. 
Mr. Fitch has this year communicated to me his latest 
discoveries of Mastodontal and other Mammalian remains 
in the crag formations of Norfolk, and he has been so 
obliging as to forward to me the specimens for description. 
In a note dated “ Norwich, September 6th, 1844,” he says: 
‘Since you last saw my collection, I have added several 
very good specimens, which I think you would like to hear 
about, if not to see. I have obtained several other Mas- 
todon’s teeth, one beautifully perfect, and precisely similar 
to one figured in the Geological Transactions, vol. vii. pl. 
xxxix. figs. 1, 2, and 3. I have also what I suppose to be 
the tooth of a Trogontherium, and a tooth I imagine to 
be of a Bear. I shall be very happy to send them up for 
your inspection, if you think them of any interest. They 
