322 



MAMMALIA. 



Fam. Georhychidse. Spalax typhlm Pall., Blindmouse, South East Europe ; 

 Georhychus capensis Pall. 



Fam. Castoridae. Beavers. 



Grinders : - 



With flat, scaled swimming-tail 

 Castor 



Two glandular sacs which secrete the castoreum open into the prepuce. 

 fiber L., the common Beaver. 



Fam. Myoxidse. Dormice. Connecting links between the Mice and Squirrels. 

 Myoxus Glis Schreb., Dormouse ; M. (Muscardinus) .avellanarius L. ; M. 

 (Ellomys*) nitela Schreb. 



Fam. Sciuridee. Squirrels. Grinders : 



6(4) 



Sciurus vulgaris L., Europe 



and North Asia ; Tamias striatus L. ; Pteromys volans L.. Flying Squirrel, 

 Siberia; Spcrmopliilus Citillus'L^ East Europe; Arctomys marmota Schreb., 

 the Marmot, Alps; A. bobac Schreb., Poland.' 



Order 9. INSECTIVORA. 



Plantigrade Mammals with clawed digits, with complete dentition, 

 small canines, and sharp-pointed grinders. 



Small Mammals, which resemble in their appearance different types 

 of Rodents, but in structure and mode of life approach the Carnivora. 

 The head ends with a pointed snout, which is often elongated like a 



proboscis. The external ears 

 are sometimes large, and some- 

 times reduced; the eyes are 

 always small and reduced, and 

 sometimes hidden beneath the 

 fur. The dentition (fig. 697) 

 is especially important, and re- 

 sembles that of the insectivorous 

 Bats. All the three kinds of teeth are present. The incisors are 

 usually of considerable size, but of variable number. The canines 

 are not always clearly distinguished from the incisors and the front 

 grinders. The grinders are numerous, and have sharply-tuberculated 

 crowns, and are divided into anterior prsemolars, of which the pos- 

 terior corresponds to the carnassial tooth of the true Carnivora, and 

 into posterior molars, which are characterized by being composed of 

 prismatic divisions. All are plantigrades, with naked soles, and 

 usually five-toed feet, armed with strong claws. The mammae are 

 abdominal ; the placenta is discoidal. They feed on small animals, 

 principally on Insects and Worms, which they destroy in great 

 numbers, thereby benefiting man. 



Fia. 697. Skull of Erinaceus europaus. 



