INSECT-EATING MAMMALS 69 



period of the Tertiary Epoch. The present distribution of 'Talpa 

 europ<ea, besides England and Scotland, extends at the present day- 

 over the greater part of Central Europe and Asia. It is found in 

 Japan and in the Himalaya and Siberian mountains. 



FAMILY : SORICID&. THE SHREWS 



The Shrews are Insectivores of small size and mouse-like 

 appearance. Some members of this family (but not the British 

 species) are remarkable for possessing an archaic feature sug- 

 gestive of the earliest types of the Mammalia. Instead of there 

 being three external and unconnected orifices in the female (the 

 anus, urinary meatus, and vagina) for the separate excretion of 

 the contents of the intestinal canal, the urethra, and the womb, 

 there is but one ; these passages opening into a common cloaca, 

 or vestibule, which, though shallow, is still a single orifice 

 externally for these three canals. This is the condition met with 

 in the Monotremata (such as the duckbill of Australia), which for 

 this reason are separated from the rest of the Mammalia into a 

 sub-class. In another respect the shrews are thought to be 

 archaic, in that they possess four incisors on each side of the 

 upper jaw, a condition similar to what obtains in so many 

 marsupials. This point, however, is not quite certain, as the 

 fourth incisor may prove to be a canine, and the so-called canine 

 a premolar. 



The family of Shrews contains the smallest known mammal, 

 Sorex suaveolens. The next smallest in size is the British species, 

 Sorex minutus. 



GENUS : SOREX. THE TRUE SHREWS 



In these little animals, two representatives of which are 

 found in Britain, the openings of the female generative and 

 urinary organs are separated from the anal orifices. The teeth 

 are coloured red at their extremities, and offer noteworthy 

 features. The first incisor in the upper jaw is developed inta 

 a large two-pronged hook. The second and third incisors, the 

 tooth which is taken to be the fourth incisor, and the canine 



