_Chironectes_ is hardly different from _Didelphys_. It has webbed hind-feet, and is aquatic in habit. The one species of the genus is known as the Yapock, and is a Central and South American form. It is of about the size of a large rat, and appears to be an expert diver after the fish upon which it lives. FAM. 3. PERAMELIDAE.--The Bandicoots, although clearly belonging to the Polyprotodont Marsupials, yet agree with the Diprotodonts in the fact that the second and third toes of the feet are bound up in a common integument, which is not the case with the Diprotodont _Caenolestes_. The hind-feet are longer than the front; of the former limb, two or three of the fingers alone are long and functional; the others are rudimentary or absent. Tail long, hairy, and non-prehensile. Dentition I 5/3 C 1/1 Pm 3/3 M 4/4 = 48, or sometimes, owing to the absence of a pair of upper incisors, 46. There is a caecum. {157} [Illustration] FIG. 85.--Bones of manus. A, of _Choeropus castanotis_. x 2. B, of Bandicoot (_Perameles_). x 1-1/2. _c_, Cuneiform; _l_, lunar; _m_, magnum; _R_, radius; _s_, scaphoid; _td_, trapezoid; _tm_, trapezium; _u_, unciform; _U_, ulna; _I-V_, digits. (From Flower's _Osteology_.) [Illustration] FIG. 86.--Rabbit Bandicoot. _Peragale lagotis._ x 1/5. The genus _Peragale_, the Rabbit-Bandicoots, consists of two species entirely Australian in range. The enormous ears (whence "Rabbit" Bandicoot) distinguish this genus from _Perameles_. The pouch opens backwards, and there are eight mammae. _P. lagotis_, the only species about whose ways of life anything is {158} known, burrows in the soil, whence it extracts grubs; it is also a grass-feeder, and it is said that its likeness to a Rabbit in appearance is strengthened by its similarity in flavour! _Perameles_ is a genus consisting of twelve species, which are found in Tasmania, Australia, and New Guinea. Like the last genus, from which it does not widely differ in other points, _Perameles_ consists of species which combine insectivorous and vegetarian habits. One species is said to become in captivity an expert in catching mice. The pouch opens backwards, and there are six or eight mammae. [Illustration] FIG. 87.--Pig-footed Bandicoot. _Choeropus castanotis._ x 1/3. The last genus of this family is _Choeropus_, containing but one species, _Ch. castanotis_. It is confined to the Australian continent. It is to be distinguished from the last two by the fact that there are only two functional digits, the second and third, in the fore-limb; the fourth is rudimentary; the other two are absent. It burrows, and is omnivorous like its allies. The two metacarpals that are developed are very long and closely apposed; they have hence a remarkably pig-like aspect, and justify its name. The pouch opens backwards, and there are eight mammae. FAM. 4. NOTORYCTIDAE.--This family contains but a single genus and species, the recently-discovered _Notoryctes typhlops_.[97]