APPENDIX. 2Q1 
similarly elongated muzzle, smooth and rounded brain-case, 
and obsolete supraorbital and cranial crest and ridges; the 
zygomata are, however, so much more boldly expanded as 
somewhat to spoil the resemblance, which in any case does 
not apply to details. Nasals long, thin, anterior two-thirds 
narrow, almost parallel-sided, but a little tapering forwards, 
their posterior third well expanded, somewhat as in ordinary 
Didelphys, but not expanded enough to meet the upper edge 
of the maxiilary bone. As a result, an ante-orbital vacuity is 
Jeft on each side in the position of, and formed exactly in the 
same way as, that of so many Ruminants. Apart from the 
latter group, this vacuity is perfectly unique among Mammals, 
and therefore well worthy of special note.” 
The dentition may be expressed by the formula i. $; c. 4; 
p. 3; m. 4; = 46. Generally, the teeth present a considerable 
resemblance to those of the Australian Dromucia, especially as 
regards their relative proportions. The canines are as well 
developed as in an ordinary carnivorous Marsupial. By Mr. 
Thomas the molars are described as “‘low-crowned, with low, 
rounded, or scarcely pointed cusps, not unlike those of Pe/aurus 
or Dromicia; the two anterior square, quadricuspidate, although 
apparently there are only three roots to each, the postero- 
internal cusp being placed on a sort of flange overhanging the 
palate, and not supported by a root; third molar similar, but 
without the extra postero-internal cusp; last molar minute, 
triangular, as small in cross section as the last incisor.” 
The selvas are so called on account of the type specimen of 
the larger species having been discovered on an estate of that 
name. Their special interest centres on the evidence they, 
in association with the occurrence of fossil Dasyurine Marsupials 
in Patagonia, afford of a former land connection between 
Australia and South America, to which allusion has already 
been made on page 5 of the text. 
U2 
