Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/698

 in Plate XXXIV. fig. 1. During the past year I have examined the collections of Mr. Whincopp, of Woodbridge, of the Rev. H. Canham, of the Mayor of Ipswich, of the Ipswich Museum, of Mr. MacLean of Yarmouth, of Mr. Roper of Lowestoft, of the British Museum, and others less extensive, with the view of obtaining further evidence as to this new British Mastodon. The result has been that in Mr. Whincopp's collection I observed two fragments consisting of two constituent ridges of a mastodont molar quite distinct from M. arvernensis. In the collection of Mr. Canham I found three fragments, two of which are here figured (Pl. XXXIV. figs. 3, 4), one of which is very similar to those belonging to Mr. Whincopp ; in the British Museum three similar fragments were detected with the aid of Mr. Davis, one (no. 27850) consisting of 2-1/2 ridges, two others (28994 and 28253) being terminal ridges with a talon like that in the figure. These eight fragments do not furnish evidence of the Tetralophodont or Trilophodont character of the teeth from which they came ; but they agree in important characters with the thoroughly typical three-ridged molar belonging to Mr. Baker. In the collection of Mr. Roper, of Lowestoft, I observed a much worn Mastodon molar presenting but three widely set ridges ; and a similar specimen was purchased by Mr. Charlesworth at Felixstow in the summer.

The perfect molar* of Mr. Baker, and the fragments since observed, belong to that form of Mastodon tooth which is furthest removed from that of M. arvernensis, the only Mastodon hitherto known in the Suffolk bone-bed. In place of the complicated interrupted valleys of that species, we have wide and clear valleys with simple primary transverse ridges, such as Mastodon ohioticus presents.

Mastodon Borsoni, which presents free valleys and a three-ridged structure of the penultimate and anterior molars, is found in association with Mastodon arvernensis in Central France ; hence it is not improbable, prima facie, that the new Crag Mastodon belongs to that species. A close comparison of specimens is, however, difficult, for we have no specimens of molars of M. Borsoni in the public collections of this country, and moreover the material at present obtained from the Crag is scanty. It is unfortunate (though of exceeding interest from another point of view) that the valleys in Mr. Baker's otherwise perfect specimen are occupied by a sandstone matrix, that of the Diestien " box-stones," which cannot be removed ; hence the character of the transverse valleys in this specimen is not quite clear. Mr. Canham's and other specimens, however, show perfectly simple valleys, agreeing with those of Borsoni, with one exception, the fragment drawn in Pl. XXXIV. fig. 4.

If not M. Borsoni, the only other species which the new Suffolk

of the specimen, after inspecting a cast of the upper surface, and would look upon it as a fragment of an ultimate molar of Tetralophodon longirostris. I must, therefore, insist especially on the fact that this is a perfect enamel crown, of three ridges ; and my friend Mr. George Busk, F.E.S., than whose no better opinion can be found, authorizes me to state that this is his opinion also, after careful examination of the specimen.
 * M. Lartet, of Paris, has expressed to me doubts as to the complete character