222 



A NEW GENUS OF EXTINCT MUSCARDINE RODENT. 



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

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

 working in the Geological Department of the British Museum 

 (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 valuable investigations into the enamel structure in the 

 teeth of Hypnomys and other genera. 



EXPLANATION OF PL A TP] I. 



Fig. 1. Hypnomys mahonensis. Tj-pe-specimen (P.M. M 11657). Palate showing 

 the left premolar and molars and right M 1 . X 4. 



2. Do. Side view of same specimen showing anteorhital region. X 3. 



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



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

 X 3. 



4. Do. Transverse section of left M 1 (B.M. M 11661). X 4. 



5. Do. Posterior view of right M 2 (B.M. M 11660). X 4. 



6. Do. Crown view of right lower molars (B.M. M 11674). X 4. 



7. Do. Lateral inner view of right lower cheek-teeth (B.M. M 11673) . 



X 3. 



8. Do. Right M 2 (P.M. M 11675) showing posterior roots. X 4. 



9. Do. Left M 2 (B.M. M 11676) showing posterior roots. X 4. 



10. H. morpheus. Right upper incisor (B.M. M 11696), inner view. X 3. 



11. H. mahonensis. Transverse section of upper incisor (B.M. M 11662). X 4. 



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



13. Leithia melitensis. Transverse section of upper incisor (B.M. M 49345 a). 



X 4. 



14. H. mahonensis. Dorsal view of interorbital region of skull (B.M. M 11659). 



X2. 



