Of the Scaly Anteaters, Group SQUAMATA or MANIDAE, there is really but one genus, though _Phatagin_, _Pholidotus_, _Smutsia_, and _Pangolin_ have been used to distinguish various forms. The genus _Manis_ is African and Oriental in range. Dr. Jentink, who has lately revised the species, allows seven.[117] The external form of these animals is fairly well known, the remarkable scales distinguishing the Pangolins from other animals. Between the scales lie hairs, which seem to be absent in the adults of the African species, though present in the young, thus affording a convenient method of distinguishing the Ethiopian from the Oriental forms. The scales have been compared to agglutinated hairs. That they are not "merely mimetic of the Lizards' scales" is held by Weber,[118] who compares them directly with those {189} structures, as he does the scales of other mammals, such as those upon the tail of _Anomalurus_, etc. This, however, is not a universal opinion. It is true that these scales occur chiefly in the lower forms of mammals such as those under consideration, Marsupials, Rodents, and Insectivores; but the fact that the hairs are developed before the scales shows, or seems to show, that the former are the older structures, and to lead to the inference that the scales of mammals are new structures. The scattered hairs of the Pangolin have no sebaceous glands excepting on the snout. This, again, looks as if they were degenerate structures, and emphasises the non-archaic character of the scales. These animals have no trace of teeth except possibly some slight epithelial thickenings which have been interpreted as a last remnant; the tongue is suited for the capture of ants, and is therefore much like that of the not nearly-related American Anteaters. The stomach is of simple form; it is characterised by a large gland, which suggests that of the Koala (see p. 144); the intestine has no caecum. Retia mirabilia occur on the limb arteries. The placenta is non-deciduate and diffuse; it is specially compared by Weber with that of the Horse. Considering the many adaptive resemblances between this genus and the American Anteaters, especially in the mouth cavity, it is remarkable that in _Manis_ the pterygoids are not joined as they are in _Myrmecophaga_. In spite of statements to the contrary, it appears that there is sometimes a distinct lachrymal. A remarkable feature in the skeleton of _Manis_ is the singular sternum. The xiphoid cartilage is extraordinarily elongated into thin strips, which reach the pelvis and return. This state of affairs is to be found in the African species only. This structure is not comparable, as it has been said to be, with abdominal ribs such as those of the reptile _Hatteria_.