PROFESSOR OWEN ON THE AYE-AYE. 99 



d. Tympanic cavity, exposing co-articulated parts of malleus and incus. 



e. Appendicular fossa. 

 /. Foramen ovale. 



g. Foramen rotundum. 

 h. Foramen opticum. 

 i. Olfactory fossa, with cribriform plates. 

 j. Sinus frontalis. 

 k. Pituitary fossa. 

 I. External auditory foramen. 

 m. Entocarotid foramen, 

 n. Pterygo-palatine foramen. 

 0. Incisive foramen. 

 p. Vomerine fissure. 

 q. Sinus sphenoidalis. 

 s. Naso-maxillary foramen. 

 t. Dental foramen. 

 u. Mental foramen. 

 V. Antorbital foramen. 

 X. Condyloid process "1 



y. Angular process > of mandible or lower jaw. 

 z. Coronoid process J 



PLATE XXI. 



Fig. 1 . Atlas vertebra, front view. 



Fig. 2. Atlas vertebra, back view. 



Fig. 3. Atlas vertebra, side view. 



Fig. 4. Axis vertebra, front view. 



Fig. 5. Axis vertebra, side view. 



Fig. 6. Cervical vertebrae, side view. 



Fig. 7. Fourth lumbar vertebra, upper view. 



Fig. 8. Fourth and fifth lumbar vertebrae, side view. 



Fig. 9. Sacrum, upper view. 



Fig. 10. Five first caudal vertebrae, upper view. 



Fig. 11. Sternum and clavicles, front view. 



In the foregoing figures : — ax, hypapophysis of atlas ; c a, centrum of atlas, 

 anchylosed as the ' odontoid process ' with — c x, centrum of axis ; n, neural 

 arch ; n s, neural spine ; d, diapophysis ; pi, pleurapophysis ; m, metapo- 

 physis ; a, anapophysis ; z, zygapophysis ; h, hsemapophyses. 



Fig. 12. Right scapula, coracoid, and clavicle ; front view. 



