MARSUPIALIA. 105 



stomach, like the preceding family, but more complicated in- 

 testines. This family includes three branches, or sub-fami- 

 lies; Ambulaloria, (walking;) Saltatoria, (leaping;) Scan- 

 soria, (climbing.) The only genus of the Ambulatoria, or 

 Walking section, is Myrmecobius, (Gr. {ifyuii%, murmex, an ant ; 

 fiioo), biod, to live. The only species is M. fasciatus, (Lat. 

 swathed,) which feeds on ants and has the reddish black of the 

 body adorned with nine white bands, whence the specific name. 

 Its length is ten inches. The Perameles, (BANDICOOTS,) is of the 

 Leaping section, including animals which, in their general struc- 

 ture, form a link between the Opossums and the Kangaroos, evi- 

 dently approaching the latter in their form, and particularly 

 in the development of their hind quarters ; with the Opossums 

 they agree in having a simple stomach and ten incisors in the 

 upper jaw. Some species, as P. lagotis, (Gr. Aayo>g, logos, a 

 hare,) make large and almost exclusive use of vegetable food. 

 In most of this family the pouch opens backwards, the reverse 

 of what occurs in the other Marsupialia, though in P. lagotis it 

 opens anteriorly. The species are found in Van Diemens' Land 

 and in New Guinea. The Scansoria, or Climbing section, include 

 the DidelphidtB, or OPOSSUMS, in their geographical distribution 

 confined to this continent. These animals are all small, the larg- 

 est being about the same size as the domestic cat, while some 

 of them are no larger than mice. They number about thirty spe- 

 cies, ranging from Brazil to Virginia, under one genus Didelphis, 

 (Gr. dig, dis, double ; dehyig, delphis, a pouch,) with the exception 

 of a single species, found in Surinam, in size larger than a rat, 

 and from its aquatic habits, as shown by its broad webbed feet, 

 ranked as a sub-genus, under the name Cheironectes, (Gr. %elg, 

 cheir, hand ; vrjxxi\<;, nekles, a swimmer.) The true OPOSSUMS, 

 (Didelphis,) have fifty teeth, viz. : ten incisors above and eight 

 below, four canines, twelve false molars, sixteen molars. The 

 incisors are small and disposed in the form of a semi-circle ; 

 the canines are large and strong ; the molars are crowned with 

 sharp tubercles. The feet have each five toes, armed with strong 

 curved claws , the inner toe of the hind feet, however, is desti- 

 tute of a claw, and is so placed as to be opposable to the oth- 

 ers, thus constituting a true thumb. The tail is more or less 

 prehensile at the tip, and hence they are arboreal. The soles 

 of their feet are covered with a naked skin of great sensibility ; 

 the ears and tip of the muzzle are likewise naked. In some 

 species, as D. dorsigerus, (Lat. dor sum, a back ; gero, to carry,) 

 the pouch exists only in a rudimentary state, or slight folds of 

 the skin. The young of these species, when of sufficient size, 



