MARSUPIALIA. 
101 
surfaces, as in the Hodentia, of whieh this family is generally 
considered to be the Marsupial analogue. The molars are strongly 
curved, and eomposed eaeh of two parallel lobes. The general 
form is stout and squat, and the tail rudimentary, consisting of 
only from 8 to 12 vertebrae, while the Phalangers have from 25 to 
31. The feet show a slight tendency towards a syndactylous 
structure. All the three known species are represented in Case 24, 
Div. A, by skeletons and skulls. 
The Bandicoots [Peramelidce) present us with the first instance 
of a polyprotodont earnivorous dentition, that is with many 
ineisors in the lower jaw, and with the lower and upper canines 
well developed, and suited for seizing and holding small mammals, 
birds, worms, beetles, &c. Their dental formula is I. C. -}-, 
Pm. f, M. f x2 = 48. On the other hand, their feet show a 
close resemblanee to those of the diprotodont Kangaroos, so that 
these animals are in some measure intermediate between the two 
great groups of Marsupials. 
The Dasyuridce are the most highly developed carnivorous Mar- 
supials, representing in this Order the true Carnivora of the 
placental series. The best known is the Thylacine or Tasmanian 
Wolf {Thylacinus cynocephalus) , whose skull strikingly resembles 
that of one of the Dog tribe. Its dentition is I. I, C. 1 Pm. I, 
M.^X 2 = 46, the teeth being sharp and cutting, and well suited 
to its predatory habits. Its feet are of the normal mammalian 
structure, and the marsupial bones represented by unossified 
cartilages only. 
The Dasyures {Dasyurus) are smaller earnivorous forms, whieh 
correspond in their habits to the weasels, martens, and other small 
placental Carnivores, while the still smaller Phascologales and 
Sminthopsis, which range from the size of a rat to that of a mouse, 
and live on inseets, worms, &e., represent the placental Insectivora. 
Their teeth are numerous, small, and eovered with sharp pointed 
cusps. Myrmecobius fasciatus is remarkable for having the largest 
number of teeth known in any heterodont mammal, its dentition 
being I. f, C. }, Pm. M. ^ x 2 = 54. The teeth are small 
and sharply cuspidate. Its external features and its habits have 
already been referred to (p. 57). 
The DidelphyidcB, or Opossums, natives of Ameriea, resemble 
