20 



iMKIUCAX MCSKUM GLIDE LEMLETS 



Skulls of Eul(ii)uni,sii)d()n, luid also of the more prohlciuatic genus 

 M(i rlthcrium are shown in the end case. Below them are palatal views of 

 the jaws and teeth of the same genera, and above are the carefully studied 

 life-size reconstructions of the heads of the two genera, modelled directly 

 upon the fossil skulls by Mr. Krwin Christman under direction of Profe.s.sor 

 Oshorn. 



Moeritherium is likewise from the Fayum district, where it accompanies 

 Pdhroif/dsfodon in tlic Lower Oligocene, but is also found in the older })eds 



of late Eocene age beneath this 

 horizon. It has therefore been 

 regarded as representing the later 

 Eocene ancestor of the pro- 

 boscideans. Its proboscidean 

 characters, however, are by no 

 means so clearly shown, and its 

 ancestral ])()siti()n is open to 

 serious question. 



The skull is quite unlike any 

 proboscidean type, having a long 

 middle region and rather short 

 face, with no suggestion of any 

 trunk. There is a full set of 

 upper incisors and two pair of 

 lower incisors, but the second 

 u])])er and lower incisor are enlarged into stout short tusks, the upper pro- 

 jecting downward, the lower forward and upward. The cheek teeth are 

 six in each jaw, the three premolars of a simple primitive-ungulate type, 

 the true molars each with two pair of rounded cusps, imperfectly united 

 into cross crests, the third lower molar with a distinct heel. 



Dr. Andrews cites' the following characters in support of the probos- 

 cidean affinities of Morrhherium. 



1. The large size of the nasal opening, its somewhat backward situation 

 and the small size of the nasal bones. 



2. The commencement of the development of air-cells in the bones of 

 the back of the skull. 



W. The enlargement of the second incisors in both jaws to form tusks. 



4. The transversely ridged character of the molars. 



5. The sj)out-likc anterior portion of the lower jaw. 



After Oshorn 



Fig. 10. Head of Mceritfurium, modelled by 



E. Christ man under direction of Professor 



Oshorn. One-tenth natural size. 



Andrews. 1908, Guide to the Elephants Recent and Fossil. British Museum. London. 



