HOSSIL INSECTIVORA 49 
TALPIDA, OR MOLES. 
Living. Europe, Asia, northern Africa and North America. 
Eocene to Recent in Europe and North America. 
Completely subterranean, fossorial or burrowing. Incisors not 
pincer-like. A zygomatic arch present. Fore-limb very short and 
powerful, specialized for digging. 
A small skull of a primitive Mole, Proscalops, from the Mio- 
cene of Colorado is on exhibition. It is Shrew-like in several 
respects, showing an approach between the now distinct families 
of Moles and Shrews. Other fragmentary remains of Moles are 
shown. 
POTAMOGALID. 
Living. Madagascar and West Africa. Aquatic animals with 
long eel-like tails. 
SOLENODONTID&. 
Living. Cuba and Hayti. 
CENTETIDA. 
Living. Madagascar. 
Fossil species supposed to be related to these animals are 
found in the Eocene (Centetodon) and Lower Oligocene (Microp- 
mi m2 ml p4 pg 
A | 
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at ‘ i. 
FIG. 23. MICROPTERNODUS BOREALIS 
A small and primitive extinct insectivore. Lower jaw, inner and outer view, twice natural size. 
Oligocene Epoch, Montana 
ternodus) of North America. This and the following family are 
more primitive than any other mammalia in the construction of 
their teeth. 
