Deinodon horridus Leidy 1856

4. Deinodon horridus, Leidy.

This genus and species are founded on a number of specimens, consisting of fragments of teeth of a saurian reptile, discovered by Dr. Hayden.

Nine of the specimens referred to consist of crowns of teeth or of their summits, which resemble those of Megalosaurus, being compressed conical and curved, and having trenchant, dentated borders. They are generally thicker in relation to their breadth than in Megalosaurus, which might only be a specific distinction, were it not that there are several other teeth in the same collection apparently of the same animal, but quite peculiar in form.

One of the specimens is a curved conical crown, nearly circular in transverse section, having a prominent dentated ridge on each side. A second specimen is a crown, demi-elliptical in transverse section, with the posterior borders dentated. A third specimen is a small fragment of a very large tooth, apparently with nearly the same form as the latter; and a fourth specimen is a portion of the crown of a tooth, demi-elliptical in transverse section, with the posterior borders elevated but not dentated.

Had the different forms of teeth above indicated been obtained from different localities, they might have been referred to at least four distinct genera, but having been discovered together, and possessing the same structural appearances, I suspect them to have belonged to one and the same species.

The largest specimen resembling the teeth of Megalosaurus in its present condition, is 1 1/4 inches long from the apex, 2/3 of an inch broad at base, and 5 lines thick. One of the specimens, which is demi-elliptical in section, is over an inch in length from the apex, 8 lines broad at base, and 3 1/2 lines wide at the posterior surface. Another specimen, apparently with the same form as that just indicated, in its perfect condition appears to have had the crown over two inches in length, nearly an inch in breadth, and about half an inch in width posteriorly.