324 Mr. C. T. Forsyth Major on 



GymnurOMTS, gen. nov. 

 (Fam. Muridce.) 



Molars §, with flat, not tuberculate crowns, their patterns 

 presenting a superficial resemblance to Myoxus nitela. Molars 

 exceedingly small as compared to the size of the skull and the 

 whole animal, forming two parallel rows in tlie upper jaw ; 

 last molar largest in both jaws. 



8. Oymnuromys Roherti, sp. n. 



Upper parts black-grey, almost slate-coloured ; laterally 

 with tiie admixture of a few white hairs ; beneath white or 

 yellowish white. Tail scaly, almost naked, the small stiff 

 hairs being more scanty than even in Mus rattus. Ears 

 large, acute oval. Snout produced. Whiskers very long 

 (55-58 millim.). Skull low, narrow, and elongated; no 

 supraorbital crests ; parietal crests lyriform in shape. The 

 crowns of the molars present from 4 to 6 transverse narrow 

 loops ; in the upper molars one of these remains open on the 

 inner margin till the teeth are much worn, whilst they are all 

 shut out from the outer margin at a much earlier stage. In 

 the lower molars these loops are somewhat more complicated, 

 sometimes two joining together and thus forming irregularly 

 ramified patterns ; they remain for a longer time open on both 

 sides than in the upper molars. Much worn molars present 

 nothing but central islets, arranged somewhat irregularly, 

 but preserving on the whole the transverse direction. 



Pregnant females obtained on June 24th and July 17th ; 

 two foetuses in each case. 



Dimensions in millimetres : — 



M. 446, $ 

 (type). M. 510, S- 



Length of head and body . . 160 150 



tail '. ... 165 167 



,, manus 15 15*5 



„ pes M 35 



„ ear 20 21 



Dimensions of skull (M. 729, S) '■— 



Basal length 35 ; length of nasals in middle line 16'3 ; 

 length of frontals in m. 1. 13'5 ; length of parietals in m. 1. 

 6*5 ; interorbital breadth at narrowest 5 ; length of upper 

 molar series 5'8 ; length of lower molar series 6'5 ; length ot 

 interparietal in middle line 4*5. 



Ampitamb^ forest. 



Native name voalavoanala. 



I 





