A complicated series of bones are developed in connection with the =auditory capsule=, which forms a large projecting mass united with the side of the cranium and drawn out behind into a pair of strong processes, the =epi-otic= and =parotic= processes. Both these processes are connected behind with a large V-shaped bone, the _post-temporal_ (fig. 13, 1), which will be described when dealing with the pectoral girdle. The =epi-otic process= is formed by the =epi-otic=, which is continuous in front with the parietal. The =parotic process= is formed by two larger bones, a more dorsal one, the =pterotic=, and a more ventral and internal one, the =opisthotic=, which is continuous in front with the large =pro-otic=. Intervening between the pterotic and frontal is another rather large bone, the =sphenotic=, this articulates below with the pro-otic. The pterotic and sphenotic together give rise to a large concave surface by which the hyomandibular articulates with the cranium. Several of the cranial nerves pass out through the bones of the auditory capsule. The ninth leaves by a foramen near the posterior border of the opisthotic, the fifth and seventh by a notch in the anterior border of the pro-otic. A number of bones are likewise developed in connection with the orbit forming the =orbital ring=. Of these the most anterior, the _lachrymal_, is much the largest, the others are five to seven in number, the most ventral being the _suborbital_. The sclerotic coat of the eye is cartilaginous. Two pairs of bones and one unpaired bone are developed in connection with the =olfactory capsules=, of these, the _nasals_ are narrow bones lying next the lachrymals, but nearer the middle line; they overlap the second pair of bones, the irregular =lateral ethmoids=. These meet one another in the middle line, and are overlapped behind by the frontal. They articulate laterally with the lachrymal and palatine, and ventrally with the parasphenoid. In a =posterior view= the foramen magnum and the four bones which surround it and together form the occipital segment are well seen. On the ventral side is the =basi-occipital=, terminated posteriorly by a slightly concave surface which articulates with the centrum of the first vertebra. The sides of the foramen magnum are formed by the =exoccipitals=, a pair of very irregular bones, pierced by a pair of prominent foramina for the exit of the tenth nerves. The exoccipitals also bear a pair of surfaces for articulation with corresponding ones on the neural arch of the first vertebra. The most dorsal of the four bones is the supra-occipital.