new Mammals from Madagascar. 323 



7. Brachyuromys ramirohitra^ sp. n. 



Ears large, oval. Coloration of upper parts brown, abun- 

 dantly mixed with black, on the sides less dark, the black 

 hairs gradually diminishing. Lower parts fawn. Basis of 

 hairs slate-coloured. Tail furnislied above with black, beneath 

 with grey hairs. Parietal crests diverging anteriorly. Inter- 

 parietal short in transverse, but longer in antero-posterior 

 diameter than in B. hetsileoensis. Molars very large, all 

 about of equal size, the third in both jaws generally slightly 

 smaller than the other two ; the third upper one slightly 

 triangular. The pattern presented by the uniting of the 

 three enamel-lobes is as follows in moderately worn teeth : — 

 In the two upper anterior molars : (1) an anterior enamel- 

 loop, open on the inner side and running obliquely across 

 the crown, close up to the outer enamel- margin of the tootli ; 

 (2) a posterior enamel islet, smaller in transverse extent than 

 the anterior loop and almost parallel to it. In the last upper 

 molar the anterior loop is shut out very soon from the inner 

 side, so that this tooth presents two obliquely transverse 

 enamel islets, with sometimes a third smaller one, behind. 

 In moderately worn lower molars the shorter anterior loop 

 opens on the inner, the longer posterior loop on the outer 

 side, the latter remaining open for a longer time than the 

 former. 



Dimensions in millimetres : — 



Skin 



(M.429),c?, Skin M.lSlJun. 

 tvpe. (M. 509),c5^. (inspirit). 



Length of head and body . . 165 162 c. 110 



;, tail 99 89 73 



„ manus 15 16 16 



„ pes 34 52 27 



„ ear 24 24 17 



Dimensions in millimetres of skull (M. 789, ^)'. — 



Basal length 32'5 ; length of nasals in middle line 13*5 ; 

 length of frontals in m. 1. 13*5 ; length of parietals in m. 1. 6*3 ; 

 interorbital breadth at narrowest 4' 7 ; length of upper molar 

 series 8'5 ; length of lower molar series 8*5 ; length of inter- 

 parietal in middle line 5*2 ; breadth of skull between zygo- 

 matic arches 23'5. 



hoc. Ampitamb^ forest, Betsimisaraka country (on the 

 border of N.E. Betsileo), 6 hours S.E. of Fandriana. 



Native names voalavoanala, ramirohitra. 



Fossil in the lower deposits of the Children's Cave (Sirab6). 



