The skull in the Armadillos presents a number of likenesses to the other American Edentates.[110] The premaxillaries are small, but are larger in _Dasypus_ than in _Tatusia_. On the other hand the lachrymals are larger in the latter. The zygomatic arch is complete, but there is no downward process as in the Sloths. In _Tatusia_ (but not in _Dasypus_) the "short thick pterygoids add somewhat to the hard palate." This is clearly a beginning or a remnant of the quite crocodilian character of the palate of _Myrmecophaga_. In the cervical vertebrae we see the Whale-like character of fusion between individual vertebrae; and also, as in the Whales, the degree to which this fusion is carried out varies; two to four may be thus united. The additional articular facets upon the dorsal vertebrae have been already commented upon as a point of important likeness to other American Edentates. The dorsal vertebrae are commonly eleven in number, the lumbar being three. But in _Priodon_ the numbers are twelve and two respectively. There are traces to be observed of the double-headed attachment of the ribs to the sternum. The shoulder girdle of the Armadillos is somewhat diverse in form in different genera; the acromion is always large, and is remarkable in _Priodon_ for the fact that the humerus also articulates with it, its extremity being recurved, and forming a socket for this purpose. As in some other Edentates there is a second spine on the scapula behind the first. The clavicle is strong. There is some variation in the form of the manus. It is five-fingered in _Dasypus_; in _Tolypeutes_ the first digit has vanished; on the other hand, in _Priodon_, the fifth has become rudimentary {176} and the third enormously enlarged. This latter fact recalls the arrangement characteristic of _Myrmecophaga_. The pelvis is greatly attached by the ischium to the vertebral column. The femur has a third trochanter. The various forms of Armadillos are largely distinguished by the number of movable thin bands of scutes lying between the large anterior and posterior shields. Thus we have _Dasypus sexcinctus_, _Tolypeutes tricinctus_, etc. [Illustration] FIG. 102.--Pelvis and sacrum of Armadillo. _Dasypus sexcinctus._ _ac_, Acetabulum; _il_, ilium; _isch_, ischium; _obt.for_, obturator-foramen; _pect.tub_, pectineal tubercle; _pub_, pubis. (From Parker and Haswell's _Zoology_.)