NOTOTIIEIUUM MITCHBLI.II. 
239 
the inner and posterior side of the astragalus, and nearly 
touches the inner and posterior angle of the tibial trochlea. 
The length of this astragalus is 1 inches 8 lines ; its breadth 
is 8 inches 5 lines; its depth (at the base of the scaphoidal 
convexity) is 2j inches. 1 
This great fossil astragalus from Australia, Professor Owen 
remarks, offers great and remarkable peculiarities, and these 
are exclusively, but most closely, repeated in certain Australian 
genera of Mamupialia , and especially in the bulkiest of the 
existing vegetable feeders (the Wombats) which are not salta- 
torial. “ The inference can hardly be resisted, that the rest 
of the essential peculiarities of the Marsupial organization were 
likewise present in that still more bulky quadruped, of which 
the fossil uuder consideration once formed part. 2 
Nototkerium Mitcheliii . Owen*. 
With the molar teeth (at least the penultimate and last), of 
equal, or very nearly equal size, with those in the jaw of 
Nototherinm inerme , the present species has a depth of jaw 
below the middle of the penultimate molar of 3£ inches, whilst 
the more perfect portion of the jaw of N. inerme, measured at 
the same part, only gives a dimension of 2$ inches. The 
thickest part of the jaw of N. Mitcheliii , beneath the same 
molar, is 2} inches, hut in that of N. inerme it is only 1 inch 
and 11 lines. A marked distinctive character of the N . 
Mitcheliii , as compared with the N. inerme, consists in the 
1 Owen, Catal. of the Organic Remains, fcc. p. 319-20. 
- Of this singular astragalus, as well as of the half jaw of Nototkerium inerme, 
a beautiful figure will be found in the part of the College Catalogue already 
referred to. 
