142 TRANSACTIONS OF THE 



animals as the Spider-monkeys and the Howlers. In the Insectivora 

 we had no very marked characters. It includes such animals as the 

 mole, shrew, and hedgehog. To this group belongs the smallest 

 of all mammals, Sorex Etruscus, which is only two and a half 

 inches in length including the tail. Passing on we come to the 

 Cheiroptera or bats. In this order the bones of the hands are 

 greatly elongated, and have a membrane stretched between the 

 separate fingers which is attached to the sides of the animal and 

 to the feet. It is this large membrane which gives to the animals 

 their power of flight. In Britain there are several distinct species 

 of bats, all of them being very small compared with those of other 

 countries. The Rodentia, or gnawing animals, are characterized 

 by the possession of two long incisor teeth in each jaw separated 

 by a gap from the molars. These teeth are continually growing, 

 and if from any cause one be broken the corresponding one in the 

 other jaw elongates to a great extent. To this group belong siich 

 animals as the rat, hare, and beaver. The Carnivora are divided 

 into three groups — the Digitigrada, or animals that walk on their 

 toes, such as the lion and cat ; the Flantigrada, animals that walk 

 on the soles of their feet, as in the bears ; the Pinnigrada, in \\'bich 

 the legs form paddles, like what we find in the seals of our shores. 

 The Proboscidea are characterised by the absence of canine teeth ; the 

 incisor teeth are enormously developed and are termed tusks, as 

 in the elephant and mammoth. The Ungulata include the Eumin- 

 antia, such as the oxen, sheep, and deer; the Pacht/dermata, or 

 thick-skinned animals; and the Solidungula, where \hQ foot is 

 terminated by a single toe, as in the horse. The next group, 

 Cetacea, includes those animals which have a more or less fish-like 

 body, as in the whales and porpoises. The order Marsupialia 

 includes such animals as the kangaroo, and is characterised by the 

 possession of a pouch in which the young are reared. The animals 

 are chiefly inhabitants of Austi-alia. In the last and lowest group, 

 Monotremata, the jaws are destitute of teeth, and present the char- 

 acters of the bills of birds. It includes the duck-billed animal and 

 the echidna. The paper was illustrated with numerous diagrams 

 and specimens. 



21sT December, 1875. 

 Mr. James Allan, Vice-President, in the chair. 



