222 A NEW GENUS OF EXTINCT MUSCAUDINE RODENT. 



enabling me to visit Menorca. Also to Dr. A. Smith Woodward, 

 F.K.S., for continued kindness in giving me every facility for 

 working in the Geological Department of the British Musei;m 

 (Nat. Hist.), to Mr. M. A. C. Hinton for kind advice and for 

 looking over some of my material, and to Mr. J. Thornton Carter 

 for his vahiable investigations into the enamel structure in the 

 teeth of Hypnomys and other genera. 



EXPLANATION OF PLATE L 



Fig. 1. JTypnomys wahonensis. Tj'pe-specinien (P.M. M 11657). Palate showing 



tlie left premolar and molars and right M'. X 4. 

 Side view of same specimen showing anteovbital region. X 3. 

 Lateral view of right upper premolar and 1st and 2nd molars, 



showing the large confluent roots of the latter (B.M. M 11658). 



X3. 

 Transverse section of left M^ (P.M. M 11661). X 4. 

 Posterior view of right M2 (B M. M 11660). X 4. 

 Crown view of right lower molars (P.M. M 11674). X 4. 

 Lateral inner view of right lower cheek-teeth (P.M. M 11673) . 



.X3. 

 Right Ms (P.M. M 11675) showing posterior roots. X 4. 

 Left Mo (P.M. M 11676) showing posterior roots. X 4. 



10. a. morpheiLS. Right upper incisor (P.M. M 11696), inner view. X 3. 



11. a. malwnensis. Transverse section of upper incisor (P.M. M 11662). X 4. 



12. Do. Transverse section of lower incisor (P.M. M 11677). X 4. 



13. Leithia melUensis. Transverse section of upper incisor (P.M. M 49345 a). 

 X4. 



14. if. malionensis. Dorsal view of interorbital region of skull (P.M. M 11659). 

 X2. 



