An introduction to the study of mammals living and extinct / by William Henry Flower and Richard Lydekker.

Date:
1891
Catalogue details

Licence: Public Domain Mark

Credit: An introduction to the study of mammals living and extinct / by William Henry Flower and Richard Lydekker. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

    717/788 (page 697)
    erinaceus, of the upper Eocene of Hampshire, of which the corre- sponding teeth are shown in B of the same figure. In this genus, according to Dr. Schlosser, the dental formula is i f, c i, ]) f, m f, or the same as in the existing Tarsius ; but it is not improbable that in some instances the first lower premolar may have been developed. The upper molars of M. erinacetis differ from those of ilf. antiqims by the simpler structure of their columns and the smaller size of the external cingulum, which lacks the median cusp found in the latter. The angle of the mandible is produced into a large hook- like flange which at once distinguishes the genus ^./^f^^r^ from all existing Lemurs; i^j^a^S^^^ A and the anterior lower ^i!r***<:^5^:«Ajr premolar is not canine- same' deposits comes ^^^^^^^^^^^^ nearer in dimensions to f'lo-332.—TUe last five nglit upper cheek-teeth of i/tcro- M prinnrfv'i Tlio nT.,^o,. '^''nis cminuus {A) !in<i Microclimrus erinaceus {B). Twice m. L I lIMCeUS. 1 ne Uppei natural size, and natural size. molars decrease in size from the first to the third, the first and second having a median cusp in the external cingulum, by which they are readily dis- tinguished from the corresponding teeth of the under-mentioned genus Hyopsodus. The third upper molar differs from that of Hyopsodus by its small size and the abortion of its posterior columns. The skull approximates to that of the living genus Galago, exhibit- ing the same inflation of the auditory bulla. The upper molars are also not unlike one species of that genus, but the fourth upper premolar has but one outer cusp, as in Chirogaleus. The small Anaptomorphus, from the North American Eocene, has a skull of about the same size as that of the smallest species of Microclmms, but the dental formula is i f, c \, p I-, m f, and the upper molars are of the tritubercular type. The well-knoAvn Aclapis {Aphelotherium or Falceolemur), of the Upper Eocene of France and England, differs from all existing Lemuroids in possessing foui' premolars i; the dental formula being * h c T, P i, m f. The fourth upper premolar has two outer cusps^ and the upper molars (Fig. 333) resemble those of Lepidolemur and Mapalemur, while the lower canine is a well-developed tooth per- forming the usual function of biting against the canine of the upper jaw. The lower incisors have upright, spatulate crowns, as in the true Apes. The skull is said to approximate in contour to that of I ropiihecus The typical A. parisiensis is of comparatively small size, but the species of which the upper cheek-teeth are shown in ^ One specimen has been seen with only three lower premolars.