268 



SKELETON OF THE BABBIT 



ii. The ex-ocoipitals bound the foramen magnum 

 laterally, and form the greater part of the 

 condyles. Each is produced at its outer side 

 into a long, downwardly directed par-occipital 

 process, which is closely applied to the pos- 

 terior surface of the tympanic bulla. 



iii. The supra-occipital is a large median bone, 

 which completes the occipital segment above. 

 The whole bone is markedly cancellous, and its 

 outer surface is raised into a prominent shield- 

 shaped elevation, giving attachment to the 

 muscles raising the head. 



Z.S. F-Av O.F. 



F.M. B.O. B.S. PT.A.S. RL. '^■'^■ 



Fio. 41. — Lepus cuniculus. Skull from the right side. The middle 

 portion of the zygomatic arch and the right half of the mandible 

 have been removed to show the bones behind them. (a. m. m.) 



AS, ali-sphenoid. B, internal orbital foramen at the anterior end of the 

 orbital groove, through which the nasal nerve enters the nasal cavity. 

 BO, basi-ocoipital. BS, baai-spheuoid. C, occipital condyle. B, man- 

 dibular symphysis. EO, ex-occipital. F, frontal. PA, foramen lacerum 

 anterius. PM, foramen lacerum medium. G, orbital groove, for ophthalmic 

 division of trigeminal nerve. I, anterior upper incisor. IF, infra-orbital 

 foramen. IP, inter-parietal. J, lower inoisor. L, lacrymal bone. LPjlacrymal 

 foramen. M, maxilla. MN, mandible. TO", nasal bone. OP, optic foramen. 

 OS, orbito-sphenoid. P, parietal. PE, par-occipital process of ex-occipital. 

 PL, palatine bone. PM, pre-maxilla. PO, periotio. PT, pterygoid. 

 S, squamosal. SP, stylo-mastoid foramen. SO, supra-occipital. T, tympanic 

 bone. ZM, zygomatic process of maxilla, oat short. ZS, zygomatic process 

 of squamosal, cut short. 



