THE SKIN AND SKELETON 



353 



those of the chick become united together (ancliylosed) 

 in the full-grown bird ; but many bones are present in 

 the fish which have no representatives in the bird. The 

 skull consists of the brain case and the face. The prin- 

 cipal parts of the skull, as shown in the dog's, are : 

 i. The occipital bone behind, inclosing a large hole, or 

 foramen magnum, on each side of which are rounded 

 prominences, called condyles, by which the skull articu- 



FIG. 308. Skull of the Horse: i, premaxillary bone; 2, upper incisors; 3, upper 

 canines; 4, superior maxillary; 5, infraorbital foramen; 6, superior maxillary spine; 

 7, nasal bones; 8, lachrymal; 9, orbital cavity; 10, lachrymal fossa; n, malar; 

 12, upper molars; 13, frontal: 15, zygomatic arch; 16, parietal; 17, occipital protu- 

 berance; 18, occipital crest; 19, occipital condyles; 20, styloid processes; 21, petrous 

 bone; 22, basilar process; 23, condyle of inferior maxillary; 24, parietal crest; 25, in- 

 ferior maxillary ; 26, lower molars; 27, anterior maxillary foramen; 28, lower canines; 

 29, lower incisors. 



lates with the first cervical vertebra. 2. The two 

 parietal bones. 3. The two frontal bones. These five 

 form the main walls of the skull. 4. The sphenoid, on 

 the floor of the skull in front of the occipital, and Con- 

 sisting of six pieces. 5. The two temporal bones, in 

 which are situated the ears. In man each temporal is 

 a single bone ; but in most animals there are three or 

 more the periotic, tympanic, and squamosal. 6. The 

 malars, or " cheek bones," each of which sends' back a 

 DODGE'S GEN. zooi . 23 



