In Glyptodon asper (Plate XIX.), the scutes of the carapace had a beautiful rosette-like sculpture, while the sheath of the tail was entirely composed of a series of movable rings, ornamented with large projecting tubercles. The vertebræ of the backbone are almost entirely fused together into a long tube, and also are joined to the under surface of the great shield, to which the ribs are united. The cheek-teeth are sixteen in number, four above and four below on each side. These are channelled with two broad and deep grooves, which divide the surface into three distinct lobes. Hence the name of the animal. The tessellated carapace of the Glyptodon was at first thought to belong to the Megatherium, with which the remains were associated, but Professor Owen clearly demonstrated the impossibility of this idea. Fig. 51 represents Glyptodon clavipes (Owen) from the Pleistocene deposits of Buenos Ayres; but the reader will gain a much better idea of the animal by inspecting the splendid specimen of Glyptodon asper in the Natural History Museum, near the centre window at the east end of the Pavilion (Glass-case Q on plan). Plate XIX. is a restoration of another species by our artist.[58] [58] This plate is based on a beautiful drawing in a Spanish work, _Anales del Museo publico Buenos Aires_. G. Burmeister, M.D., Phil. D. Tomo Segundo. In the Museum of the Royal College of Surgeons (which the reader is recommended to visit) there are several most valuable specimens of these extinct armadillos from South America. [Illustration: Fig. 51.--Extinct Gigantic Armadillo, _Glyptodon clavipes_, from Pleistocene deposits, Buenos Ayres. (The tail sheath here represented probably belongs to another genus, Hoplophorus.)] Armadillos belong, with sloths and ant-eaters, to the same family of so-called toothless animals (edentata) with no front teeth, though one or two forms really are toothless. Those of the present day have their bony armour divided up into a series of bands, so that they can roll themselves up, more or less, into balls. They burrow under the ground, where they get their food to a certain extent, and live a safe life, protected by their casque of mail. Their only enemies seem to be the monkeys, and one of the tricks of the young monkeys in the American forests is, when they find an armadillo away from home, to pull its tail unmercifully, and try to drag it about. Snakes cannot hurt them. Mr. Hudson, in his most interesting book, _A Naturalist in La Plata_, narrates how he watched an armadillo kill a snake and then devour it.