38 REPORT OF NEW JERSEY STATE MUSEUM. 



(3) The Biitheria or modern mammals comprising all the 

 familiar species found to-day in all parts of the world, except the 

 Australian region. 



In New Jersey we have, of course, no representatives 

 of the Prototheria, while the Marsupialia are represented 

 only by the common oppossum. Of the Bnthevia, we 

 have numerous examples, although several of the orders are 

 entirely wanting, as for instance, those comprising the ele- 

 phants, sloths and monkeys. Remains of some of these, how- 

 ever, occur as fossils, in deposits in different parts of the State; 

 the most familiar being the great mastodon, a close relative of 

 the elephant, whose gigantic skull, teeth and tusks are now and 

 then brought to light when excavations are being made in the 

 earth. The several orders of mammals that are represented in 

 the New Jersey fauna may be distinguished as follows : 



a. Young born at a very early stage of development and reared in a pouch 



on the belly of the female. marsupialia (Opossum) 



aa. Female not pouched. Eutheria 



b. Aquatic, with no hind legs ; fore legs modified into flippers for 



swimming. cetacea (Whales, etc.) 



bb. Terrestrial (except seals and bats), all four limbs developed, and body 



thickly covered with hair. 



c. Nails developed into hoofs. ungulata (Deer, etc.) 



cc. Nails compressed and hooked, forming claws. 



d. Incisor (or front) teeth very prominent, two in each jaw, a 

 gap on each side separating them from the molars or back 

 teeth. GLiREs (Rats, etc.) 



dd. Incisors small, generally more than two; canine (or tyt) 

 teeth present, filling the gap between tht incisors and molars. 

 e. Fore feet developed into wings. chiroptera (Bats.) 



ee. Fore feet normal. 



f. Canines not prominent. insectivora (Shrews, etc.) 



ff. Canines prominent. carnivora (Wild Cat, Seals, etc.) 



