PHALANGERID& 147 



Family PHALANGERID.E. 



Dentition extremely variable, owing to the presence of minute 

 rudimental teeth not constant in the same species, or even in the 



two sides of the jaws of the same individual ; exclusive, however, of 



g j /2 3) (3 4) 



Tarsipes, the formula i p c ^, p }Q~^, > (3114) represents fairly the 



general condition of the functional teeth. First incisors long and 

 stout ; the lower pair very large and pointed, but withoiit the scissor- 

 like action found in the existing Macropodidw ; second and third 

 lower incisors minute and probably functionless. Fourth premolar 

 generally secant ; milk-molar generally minute and deciduous at an 

 early period. Molars either with sharp cutting-crests or bluntly 

 tuberculate ; fourth sometimes absent. Mandible without pit, and 

 at most a very minute perforation in the masseteric fossa. Limbs 

 subequal. Fore feet with five distinct, subequal toes, furnished with 

 claws. Hind feet short and broad, with five well-developed toes ; the 

 hallux large, nailless and opposable ; the second and third slender, 

 and united by a common integument as far as the claws. Tail 

 generally long, and frequently more or less prehensile. Stomach 

 simple. Caecum present (except in Tarsipes), and usually large. 

 Pouch complete. Animals of small or moderate size and arboreal 

 habits, usually feeding on a vegetable or mixed diet, inhabiting 

 Australia and the Papuan Islands. 



The homologies of the lower functionless teeth between the first 

 incisor and fourth premolar are very difficult to determine, but 

 it is probable that one represents a canine only when the largest 

 known number is present; this tooth, according to Mr. Thomas, 

 being the first to disappear. 



Phalangers are small woolly-coated animals, with long, power- 

 ful, and often prehensile tails, large claws, and, as in the American 

 opossums, with opposable nailless great toes. Their expression 

 seems in the day to be dull and sleepy, but by night they 

 appear to decidedly greater advantage. They live mostly upon 

 fruit, leaves, and blossoms, although some few feed habitually upon 

 insects, and all relish, when in confinement, an occasional bird 

 or other small animal. Several of the Phalangers possess flying 

 membranes stretched between their fore and hind limbs (Fig. 48), 

 by the help of which they can make long and sustained leaps 

 through the air, like the Flying Squirrels, but it is interesting to 

 notice that the possession of these flying membranes does not seem 

 to be any indication of special affinity, the characters of the skull 

 and teeth sharply dividing the flying forms, and uniting them with 

 other species of the non-flying groups. Their skulls (Fig. 47) 

 are as a rule broad and flattened, with the posterior part swollen 



