The cranial portion of the dorsal surface is formed by the maxillary (8), nasal (7), and premaxillary bones (9). Just craniad of the nasals, bounded ventrad and craniad by the premaxillaries, appears the large opening of the nares (_j_), leading into the nasal cavity. The =zygomatic arch= (_g_) is formed by the zygomatic process of the temporal (_m_) and the malar or zygomatic bone (6). Each presents near its middle a prominent dorsocaudally directed process, the frontal process (_h_) of the malar bone. The zygomatic arch forms the lateral boundary of the temporal and orbital fossæ, which are separated by a line connecting the frontal process of the malar (_h_) and the zygomatic process of the frontal (_f_). A portion of the floor of the orbit and the opening of the lachrymal canal (_o_) may also be seen in dorsal view; they are described in connection with the lateral surface. The =caudal surface= of the skull is formed largely by the occipital bone (Fig. 17), surrounding the foramen magnum (Fig. 17, _d_). At the sides of the foramen magnum are the two prominent curved occipital condyles (_e_) for articulation with the atlas. Craniolaterad of the condyles, separated from them by a deep notch, are the jugular processes (_f_) of the occipital, closely applied to the caudal ends of the tympanic bullæ. Dorsad of the foramen magnum are faint indications of a median ridge running dorsad, the =external occipital crest= (Fig. 17, _i_); this rises at its junction with the lambdoidal ridge to form the prominent =external occipital tubercle= (Fig. 39, _b_). The dorsal and dorsolateral boundaries of the posterior surface are formed by the lambdoidal ridge (Fig. 17, _h_; Fig. 39, _a_). The =lateral surface= of the skull (Fig. 40) is much more complicated than the dorsal and posterior surfaces. Caudally the occipital condyles (_a_) and external occipital crest (_b_) are visible; dorsocaudad the sagittal crest (_c_). Extending from the caudal end of the sagittal crest the lambdoidal ridge (_d_) is seen passing ventrocraniad to the tympanic bulla, thence craniad to the root of the zygomatic arch. In the ventral part of the caudal region the tympanic bulla (_e_) is visible with the jugular process (_f_) of the occipital pressed close against its caudal end. Just craniad of the jugular process the mastoid process (_g_) of the temporal rests against the side of the bulla. Beneath the cranial edge of this process is the opening of the stylomastoid foramen (_h_) for the seventh nerve, while just ventrad of the foramen is the small pit (_i_) in the tympanic bulla for the reception of the tympanohyal bone. Craniad of the stylomastoid foramen is the large opening of the external auditory meatus (_j_), leading into the middle ear.