Page:Quarterly Journal of the Geological Society of London, vol. 35.djvu/620

524 the two anterior and one of the middle ridges, the remainder of the crown having been broken recently and lost.

The other tooth is still more imperfect, only one of the anterior and middle nipples remaining. It differs, however, from the former crown; for whilst its anterior ridges have also been quite recently broken off, the surface of the tooth, where the two companion ridges of those still extant should be, is firmly incrusted with the matrix, showing that the enamel had been denuded prior to or during the imbedment of the tooth.

Both molars have the bases of their crowns where the fangs originate also covered with the characteristic calcareous sandstone of the islands.

Mr. Wright informed me that he procured the specimens from a native boy, and that he visited the spot and fully confirmed the statements of the finder. The specimens were found at different times by the same lad, and were cut out of the solid compact Calcareous Sandstone.

The specimen fig. 5, was discovered in October 1871, on one of the "nodule-seams" of the Calcareous Sandstone, close to the shore, and nearly at the sea-level, in the Bay of Marsa el Forno, on the N.E. of Gozo.

The other tooth "was found in December 1873 in the same horizon, but at a distance of a few hundred yards further westward, near the promontory called Kola Baida."

The characters and state of detrition of the crowns are the same in both teeth, which are no doubt penultimate molars.

That they belonged to a trilophodont Mastodon seems to me probable from the diminished extent of continuity, indicating a surface barely sufficient for two additional ridges, and which must have been smaller a good deal than those still existing.

Both molars, especially that shown in fig. 5, display much roughening (r) of the enamel around the base of the ridges and outlying mamillæ. In these respects, as in the presence of other digitations on the crown and sides of the ridges, they approach M. angustidens rather than M. Borsoni in character.

A broad pressure-mark (p) is seen on either tooth on the talon.

The dimensions and characters, so far as procurable, agree with those of the penultimate of M. angustidens; but altogether they are insufficient for the differentiation of species.

, Owen.

Professor Owen, to whom I sent the teeth (Pl. XXV. figs. 1, 2) from Malta, has named them rugosidens, from the pronounced roughening of the enamel. Altogether four specimens were discovered in the Calcareous Sandstone of Gozo, two of which, from Mr. Wright's collection, are also represented with the above.