1903.] Matthew, Fossil Hedgehog from Ajnerica?i Oligocene. 229 



Mi and m^ wider than long, quadrate with two external and two 

 internal cusps of about equal size and a small separate postero- 

 intermediate cusp (metaconule) , the antero-intemal cusp (protocone) 

 with a ridge running out towards the antero-external margin. M^ 

 trihedral, small, not extended transversely, paraconid and metaconid 

 equal and well separated, no hypocone. Palate completely ossified, 

 its posterior margin as in Erinaceus. Skull bones arranged much as 

 in Erinaceus , a well defined sagittal crest; premaxillas not reaching 

 frontal bones. 



Measurements. 



Maxillary dentition, c-m3 inclusive 18.4 mm. 



Transverse width of palate including molars 17.6 



Depth of skull, junction of postorbital crests to 



palate 16.8 



Length of three true molars (antero-posterior) .... 7.9 

 Antero-posterior diameter of m^ 3.4 



Transverse 



Antero-posterior 



Transverse 



Antero-posterior 



Transverse 



m3. 



4.8 

 2.9 



3-9 

 2.0 

 2.8 



Range of the Erinaceid^ and Leptictid^. 



