EROEESSOR OWEN ON THE EOSSIL MAMMALS OE AUSTRALIA. 
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Fig. 29. Working-surface of left lower molar, Macropus Titan. 
Fig. 30. Idem, Sthenurus Atlas. 
PLATE XXI. 
Fig. 1. Working-surface of right upper molars, Macropus major. 
Fig. 2. Idem, Macropus rufus. 
Fig. 3. Idem, Ospliranter robustus. 
Fig. 4. Working-surface of right lower molars. Macropus rufus. 
Fig. 5. Idem, Boriogale magnus. 
Fig. 6. Outer side view of left maxillary bone and molar series of a young Macropus 
Titan. 
Fig. 7. Inner side view of left maxillary bone and molar series of a young Macropus 
Titan. 
Fig. 8. Working-surface of molars of left maxillary bone of a young Macropus 
Titan. 
Fig. 9. Back view of the same fossil, showing formative cell of the last molar, m 3. 
Fig. 10. Palatal or under view of a left maxillary, with working-surface of the molar 
teeth of an older Macropus Titan. 
Fig. 11. Working-surface of right upper molar series of a mature Macropus Titan. 
Fig. 12. Working-surface of the last two lower molars, right side, Macropus Titan. 
Fig. 13. Outer side view of the same teeth, with outline of part of mandible. 
Fig. 14. Inner side view of the same teeth, with outline of part of mandible. 
Fig. 15. Under or palatal view of right maxillary bone and teeth of an old Macropus 
Titan. 
Fig. 16. Outer side view of right maxillary bone and teeth of an old Macropus Titan. 
Fig. 17. Inner side view of teeth of right maxillary hone of an old Macropus Titan. 
Fig. 18. Hind surface of last upper molar (to 3 ) of an old Macropus Titan. 
PLATE XXII. 
Fig. 1. Outer side view of part of right maxillary and teeth of a young Phascolagus 
altus ; the premolar (p 3) and penultimate molar (to 2) are exposed in their 
formative alveoli. 
Fig. 2. Under view of the same specimen. 
Fig. 3. Upper view of portion of right mandibular ramus, showing the working-surface 
of the molars in place, and of the crown of the last molar ( to 3) in its forma- 
tive alveolus, of a young Sthenurus Atlas. 
Fig. 4. Outer side view of part of the same specimen, with the crown of the premolar 
exposed in its formative alveolus. (These figures are from the type spe cimen of 
Macropus Atlas, O w., figured in Mitchell’s ‘Three Expeditions,’ &c., 8vo, 
vol. ii. 1838, p. 359, pi. xxix. fig. 1.) 
