XXII. I 



INSECTIVORES 



583 



of Mongolia and having characters very close to those of the ancestor 

 not only of insectivores but of all placental mammals. The skull was 

 tubular and elongated, but without the special snout of some modern 

 forms. The teeth are of special interest in that in the upper molars the 

 central cusp (amphicone) showed only partial division into paracone 

 and metacone. There were large canines and other features suggesting 

 creodonts. 



Classification of the various lines of insectivores has been difficult, 

 as might be expected in a group containing surviving ancient as well 



Fig. 358. Tenrec. 

 (From photographs.) 



Fig. 359. Solenodon, alamiqui. 

 (After Cambridge Natural History.) 



as modified types. It is not feasible here to discuss the possible 

 affinities of the various groups. 



Tenrec (Fig. 358) from Madagascar, and Solenodon, the alamiqui 

 (Fig. 359), from the West Indies are remarkably similar animals, 

 showing in their dentition, brain, and other features characters more 

 primitive even than those of other insectivores. The teeth have a 

 tritubercular V pattern, by which they are sometimes distinguished 

 as 'zalambdodont' from the remaining or 'dilambdodont' insectivores. 

 The resemblance of the alamiqui and the tenrec has often been cited 

 as evidence of a land bridge, but is probably a result of retention of 

 primitive features. Potamogale (the otter shrew) is a related aquatic 

 African form, feeding on fish. 



The golden moles (Chrysochloris) of Africa are burrowing animals, 

 with interesting features of similarity to the marsupial and true moles. 

 Hedgehogs (Erinaceiis) (Fig. 360) are mainly nocturnal creatures, 

 feeding on a mixed animal diet of insects, slugs, small birds, and snakes 

 or even fruit. They have a remarkable immunity to snake-bite and 

 indeed to bacterial and other toxins. Related genera in South-east 

 Asia, such as Echtnosorex, are more primitive in that the hairs of the 

 back are normal, and not converted into spines as in the hedgehogs. 

 In the Oligocene and Miocene of Europe both types were equally 

 common. The shrews (Soricidae) are mouse-like, insectivorous and 

 omnivorous animals of various types, some terrestrial, others aquatic, 



