350 THE INSECTIVORES 



Probably more or less closely allied to the potamogale is a small 

 Geogale mouse-like Insectivore from Madagascar, described under the name of 



Geogale. This creature has thirty-four teeth, which resemble in form those of the 

 potamogale, but our information is at present insufficient to render us certain as to 

 its full affinities. 



THE GOLDEN MOLES 

 Family CHRTSOCHLORID^E 



The golden or Cape moles, constituting the genus Chrysochloris, are so differ- 

 ent from all other Insectivores of this group that they are referred to a distinct fam- 

 ily. They are entirely confined to South Africa, where they are represented by 

 about seven species, and are commonly termed moles by the colonists. 



The skull of the golden mole differs from that of the tenrec in possessing a dis- 

 tinct zygornatic arch below the socket of the eye, and also in that its tympanic bulla 

 is bladder like. In appearance these animals have some resemblance to the moles, 

 but they have shorter and thicker bodies, with a deeper head and blunter snout. 

 The whole form is, however, admirably adapted for tunneling through the ground : 

 since the eyes are totally covered beneath the hairy skin, and the minute ears are 

 deeply buried in the fur. While the hind-feet retain a normal form, the fore-feet 

 have been specially modified for the purpose of digging, having only four toes, of 

 which the two central ones are furnished with enormous triangular claws of great 

 power. The more typical species have altogether forty teeth, but in others the 

 number is reduced to thirty-eight, owing to the loss of the first pair of premolars 

 in each jaw. The molar teeth have very tall crowns. The golden moles derive 

 both their popular and scientific names from the brilliant metallic lustre of the fur, 

 which shows various tints of green, violet, or golden bronze ; the brilliancy of these 

 metallic hues being much intensified when the skin is immersed in spirit. 



The runs are made so near the surface of the ground that the earth 

 is raised above the tunnel, which can accordingly be followed with ease 

 in all directions. When one of the moles is seen to be at work, owing to the move- 

 ments of the soil, it can readily be thrown up on to the surface by the aid of a stick 

 or spade. The food of the golden moles consists mainly of earthworms. 



The nearest relatives of the golden moles appear to be the tenrecs, while the 

 ordinary moles are closely allied to the shrews ; and it is thus interesting to find two- 

 widely different groups of animals modified for a similar kind of subterranean life. 

 This modification has, however, by no means followed the same lines in the two- 

 groups, for not only do the skeletons of the golden and true moles differ consider- 

 ably from one another, but there is a still more marked difference in the form and 

 structure of the fore-foot. Thus, whereas the fore-foot of the true mole has as- 

 sumed the well-known hand-like form, with an additional sickle-like bone near the 

 thumb, that of the golden mole, as we have just seen, is of a totally different type, 

 the power of digging being mainly due to the enormous horny claws of its two- 

 middle fingers. 



