1902.] 



DR. C. I. FORSYTH MAJOR OX PLIOCENE VOLES. 



103 



mostly isolated teeth — are so minute and fragmentary, that I have 

 to supplement my demonstration by sketches. 



The jaw from the Yal d'Arno (text-fig. 13, nos. 8, 9), con- 

 taining two anterior rooted molars, was mentioned by me 

 upwards of twenty years ago. The first lower molar (text- 

 fig. 13, no. 8) exhibits in its anterior portion an enamel islet, 

 which is a very strange feature in a Yole's molar. I am sorry 

 to trouble members with such a minute detail ; but almost the 

 whole interest centres around this insular eccentricity, so to 



Text-fig. 13. 



Teetli and Jaws of Tertiary Voles, 



H. G-. del. 



Figs. 1-5 & 7 represent the first lower molars, upper view. — Fig. 1. Ilhnomys 

 intermedius (Newt.), "West Eunton Forest Bed (B. M. No. 6968 d, from Savin 

 Coll. No. 1705) : left side. — Figs. 2 & 3. Mimomys plioceenictis (Maj.), 

 Norwich Crag, Thorpe (Norw. Castle Mns. No. 971) : fig. 2, left sidej fig. 3, 

 right side. — Figs. 4 & 5. 3Iimomys pUocaniciis (Maj.), Norwich Crag, Thorpe 

 (Norw. Castle Mus. No. 551, from Fitch Coll.) : fig. 4, right side ; fig. 5, left 

 side (figm'ed by E. T. Newton, ' Forest Bed,' pi. 13. fig. 13).— Fig. 6. Mimomys 

 plioceenicus (Maj.), third upper molar, left side; East Runton Forest Bed 

 (B. M. No. 6967, from Savin Coll. No. 464). — Fig. 7. Mimomys netvfoni, sp. n., 

 East Runton Forest Bed (B. M. No. 6967 a, from Savin Coll. No. 430) : left 

 side. — Fig. 8. Mimomys plioceenicus (Maj.), first and second lower molars, 

 upper view ; Upper Val d'Arno, Italy (Florence Museum). — Fig. 9 a. The same 

 specimen, outer view of the mandible, nat. size. — Fig. 9 h. The same enlarged, 

 r=root of m^— Fig. 9 c. The same mandible, inner view, enlarged. 



