THE OPOSSUMS. 219 



There is a little kind, measuring only three inches in length, with white fur everywhere, except on 

 the upper parts, which are ashy grey ; and in Western and Southern Australia there is one which has 

 great ears, very slender limbs, and a short and thick fat tail. It looks like a large-eared, fat-tailed 

 Mouse, and is under four inches in length. All these kinds of Phascogale, except the brush-tailed one, 

 belong to a group with very short hairs on the tail, and are sometimes classified under the name 

 Antechinus, the thick-tailed one being termed Podabrus ; and they all have shallow pouches. 



CHAPTER III. 



THE OPOSSUMS. 



Prehistoric Opossums Description of the Animal Their Teeth Habits THE COMMON OPOSSUM D'AZAKA'S OPOSSUM 

 THE CRAB-EATING OPOSSUM THE THICK-TAILED OPOSSUM MERIAN'S OPOSSUM Pouchless Opossums Their Young 

 THE MURINA OPOSSUM THE ELEGANT OPOSSUM THE YAPOCK Classification of Marsupial Animals Geographical 

 Distribution of the Sub-Order Ancestry of the Marsupials Fossil Remains. 



VI. THE OPOSSUM FAMILY. DIDELPHID^}. 



THE Marsupial animals included in this family are not found in Australia or in Yan Diemen's 

 Land, or in any part of the natural history province to which those countries belong. They are 

 numerous, however, and are now living on the American continent ; but formerly some inhabited 

 Europe during that geological period which is called the Eocene. The Opossums are very rat-like in 

 form, the largest species being about the size of a large Cat, but they have the snout more elongated ; 

 and in some species in which the individuals are large the body is proportionately stout, and on most 

 there is a comfoi-table fur, with short and long hair. The tail is almost always very long, nearly 

 destitute of hair, excepting at the root, and is covered with a scaly skin, there being a few scattered 

 hairs. It is a useful organ, for the Opossums hang by it, and it assists them in climbing and descending 

 trees, and in holding on, when they are young, to their parent. The ears are rather large and round, 

 the eyes are placed rather high up in the face, and the long muzzle ends in a naked snout. The 

 legs look short for the body. The feet are naked 

 beneath ; there are five toes, and the great toe is 

 more or less opposable to the foot, and acts like a 

 grasping thumb. Each toe is furnished with 

 moderate-sized claws, excepting the inner toe of 

 the hind foot, which is clawless. The Opossums 

 are remarkable for the great number of their 

 incisor teeth, there being ten in the upper and 



eight in the lower jaw, and they are arranged in TEETH OF THE OPOSSUM. 



a semicircular manner. The upper and two fore- 

 most incisors are rather longer than the rest, and are generally separated from them by a narrow 

 space. They are nearly cylindrical and expanded at the tip. The canines are well developed, the 

 upper ones being the largest. There are three premolars on each side of both jaws, and they have 

 two roots, and are compressed and pointed. There is a posterior talon to them. The molars, eight 

 in each jaw, have three roots, and those of the upper jaw have the crown of a triangular form and 

 tubercular, whilst those of the lower jaw are longer than broad, and each has the appearance of five 

 prickly cusps on its upper surface. 



Some of the Didelphidae have no marsupium, or pouch, or it is very slightly developed, and in 

 these particular kinds the young, after having left the nipples, are carried on the back of the mother, 

 retaining their position by twining their tails around here. The mammae are numerous : there may 

 be as many as thirteen, an odd one being found in the centre of the ring of the other nipples. 



The Opossums are active, sly, and very intelligent in certain things, and their food consists of 

 insects, small reptiles, birds, and eggs. Living for the most part in trees, they secrete themselves in 



