[Illustration: FIG. 114. Face view of the Gibraltar skull (left) and of a modern Australian skull (right), displaying the high, large visage of the former, which suggests that of the anthropoid apes. After Schwalbe. One-quarter life size. The comparative horizontal lines are across the (_a_) _nasion_, or root of the nose, the (_b_) lower edges of the orbits, and the (_c_) lower edge of the nasal aperture.] Like the Heidelberg jaw, that of the Neanderthals is distinguished by great thickness and massiveness. In general the contours are similar; in a few instances the chin process is suggested by a slight prominence, but in general the chin is strongly receding, and it agrees with that of Heidelberg in lacking the _spina mentalis_. In other characteristics there are decided differences in the Heidelberg and Neanderthal jaws. The form of the latter is now known from the specimens of Krapina, of Spy, of La Naulette, of Ochos, and of Šipka, and from the perfect examples of Le Moustier and La Chapelle. The Šipka specimen proves that even in a child ten years of age the jaw was remarkable for thickness and strength. Boule(52) entirely agrees with Gorjanovič-Kramberger(53) that the chin in the Neanderthal jaw was only in process of formation, and throughout life attained no more than an infantile form, that the Neanderthals may be ranked, however, as _Homines mentales_, whereas the Heidelbergs, in which the chin is entirely lacking, may be regarded as _Homines amentales_. The proportions of the teeth in the Neanderthals are equally distinctive, especially in the size of the true grinders and cutting teeth. As in the Heidelberg jaw, they form a closely set row, from which the canine does not project as in the Piltdown dentition; in fact, the contour of the jaw and the proportions of the teeth are distinctly human when compared with the orang-like jaw of the Piltdown man. The grinding surface of the teeth has many layers of enamel, and the cusps are well developed. Unlike those of recent man, the incisors display folds of enamel on the inner or lingual surfaces, a condition rarely observed in the modern cutting teeth. In the teeth of the Heidelberg jaw, the pulp cavities are exceptionally large, whereas in the teeth of the Krapina race there is the unique feature that the molars have no normal roots, the roots having been more or less absorbed, a very rare occurrence in recent man. The dentition of La Chapelle is also distinctly human, but extraordinarily massive, corresponding with the general massiveness of the skull and masticating apparatus; in detail it is not that of civilized races, but an exaggerated form of the type called _macrodont_.(54) The elongation of the crown is also similar to what is termed hypsodont.