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Family MACROPODIDiE. 



Extinct Genera and Species. 



§ 1. Introduction. — As the extinct Marsupials which I now proceed to define (their 

 restoration awaiting further materials) have chiefly been made known to me by their 

 fossil jaws and teeth, some remarks on the latter organs will be briefly premised. 



The dentition of the Kangaroos (bilophodont Macropodidce*) is summarily described 

 and figured in my ' Odontography ' f : in later works J its phases of development and 

 mutation are exemplified in detail in Macropus major §. The last phase delineated 

 (Anat. of Vert. vol. iii. fig. 296, f) is that which is shown in the subject of figs. 15 & 

 16, Plate LXXX., in the mandible of Macropus major, in which the anterior of the 

 four retained molars (d 4) is " nodding to its fall." I have seen a specimen of an older 

 Kangaroo of this species in which the series of grinders was reduced to two, viz. m 2 

 and m 3. Fig. 15, Plate LXXX., is also introduced to exemplify the largest size of 

 mandible to be derived from any known existing kind of Kangaroo. The other figures 

 in that Plate show modifications in the size, form, structure, and order of succession 

 and shedding of teeth requisite for the description and comprehension of characters of 

 fossil jaws and teeth of the present family of Marsupials. 



Thus, in Macropus (Osphranter) robustus, Gd. (Plate LXXX. figs. 13 & 14), the 

 premolar (p 3), which is not larger than that in Macropus major ||, is later retained ; and 

 the following molar (d i) in my subject had undergone a much greater degree of wear 

 than in Macropus major before p 3 had risen into place. This is plainly shown by the 

 lower level of the much-worn d 4 in fig. 13. It would also seem to have been originally 

 a relatively smaller tooth than its homologue in the " greater Kangaroo." The last 

 molar is in place, and shows the same slight degree of masticatory wear in both species ; 

 but with this the molar series is reduced to four teeth in one, and shows five teeth, or 

 four and a half, in the other. 



In Macropus (Halmaturus) ualabatus, Less. & Gd. (ib. fig. 11), the premolar (p 3), 



* This is a section distinct from the Kangaroo-rats, Bettongs, &c, with quadrituberculate molars, included 

 in the subfamily Hypsiprymnidce. 



f 4to, 1840-45, pp. 389-393, pis. 100, 101, 102. 



X Art. Teeth, in ' Cyclopaedia of Anatomy,' vol. iv. ; also ' Anatomy of Vertebrates,' 8vo, vol. iii. p. 380, 

 fig. 296. 



§ I have always referred to this large and first-discovered species of Kangaroo under Shaw's later name 

 (General Zoology, vol. i. pp. 505, 800). Mr. Wateehotjse alludes to it sometimes (as in p. 52 of his excellent 

 ' Natural History of Mammalia ') as Macropus major, sometimes as Macropus giganteus (ib. p. 55), the synonym 

 of Zimmerman's Jerboia gigantea (1777) and of Schreber's Didelphis gigantea (1778). 



|| Anat. of Vertebrates, vol. iii. fig. 296, e, p 3. 



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