EXPLANATION OF PLATE VIL 



FIGURES. 



1. Notoryctes typhloijs. The skull, dorsal view (naf. size). 



a, the triple ridge on vertex for the attachment of nuchal 

 muscles. 



2. Base of skull (x 2). 



al, alisphenoid. 



eo, exoccipital. 



gf, glenoid fossa. 



m, mastoid portion of periotic 



oc, occipital condyles. 



ty, tympanic. 



3. Hyoid bone (x 2). 



hh, basihyoid. 

 th, thyrohyoid. 



4. The same from an older specimen (x 2). 



c, thyroid cartilage of larynx. 

 Other references the same as in fig. 3. 



5. Ventral view of cervical vertebra and presternum (x 2). 



a, atlas. 



h, odontoid process of axis. 



c, fused cervical vertebrae, II. — VI. 



d, body of seventh cervical vertebrae. 



e, first rib. 



/, presternum. 



fj, second rib. 



h, sternal segment of second rib. 



i, second segment of mesosternum. 



6. Lateral view of a portion of the anterior part of the axial skeleton (x2). 



h, odontoid process of axis. 



c, fused cervical vertebra — II. — VI. 



d, neural arch of seventh vertebra. 



e, first rib. 



/, keel of presternum. 

 (J, second vertebral ril). 

 h, sternal rib of above. 

 i, mesosternum. 

 h, xiphisternum. 



xxxx, cartilaginous segments of fourth, fifth, sixth, and seventh 

 sternal ribs. 



7. Xiphisternum, ventral view (x 2). 



h, marks the junction of the bonj' xiphisternum with its car- 

 tilaginous expansion. 



8. View of anterior orifice of thorax (x 2). 



d, neural arch of seventh vertebra. 



e, first rib. 



/, presternum. 



/, spinous process of eighth vertebra. 



m, transverse process of seventh vertebra. 



n, articular surfaces of first rib for the laterally expanded body 



of the sixth cervical vertel)ra. 

 o, articulation of first rib with presternum. 



9. Second lunibar vertebra, anterior view (x 2). 



a, spinous process. 



h, metapophysis. 



c, transverse process. 



d^ hypopophyses. 



7., anterior zygapophysis. 



