new Jaj)anese ^f(»llnuIs. 493 



111 no Oriental or Au&tiMlian species are tlie molars of this 

 character, but among the African forms, although in the 

 great majority as in typical .1//*?, those of Mus arborariun, 

 Peters, and JA rutHans, Peters, are almost precisely as in 

 Micromys and appear to indicate a real relationship to that 

 genus. 



In view of the immense number of species of Mas known 

 and the difKculty of dividing them into natural groups, it is 

 of great value to be able to separate off any section of them 

 by essential characters^ however slight these may appear 

 to be. 



Evotomys (Pkaulomys) Smi'thti, subgen. et sp. nn. 



Phaulomys *, subgen. nov. 



External proportions and other characters as in Evotomys, 

 although the colour tends more towards brown than the usual 

 red of Evotomys. 



Skull with the smooth non-angular brain-case characteristic 

 of Evotomys; zygomata more widely splayed; posterior 

 palate typical ; bullse unusually small. 



Teeth not rooted in the only specimen, which is fully 

 adult ; therefore if rooted at all they must only become so 

 very late in life, as in Craseomys. Base of second upper 

 molar in a distinct capsule at the bottom of the orbital fossa 

 and that of the last lower molar similarly encapsuled on the 

 inner side of the incisor-root, both as in Craseomys and 

 Microtus, not as in Evotomys. Molars very weak and narrow 

 (breadth of w* barely more than half its length, 0*8 mm. as 

 against 1"5), the few closed triangles not or scarcely broader 

 than long. General structure of teeth showing an exaggera- 

 tion of the Evotomys characters of rounded cement-areas and 

 coalescence of opposite spaces (see figure, p. 494). Last upper 

 molar more simple than in Evotomys, its second and third 

 spaces coalesced into one. B^^low the anterior molar is also 

 remarkably simph^, and in all three teeth the outer re-entrant 

 angles are nearly as deep as the inner. 



This interesting form adds another to the considerable 

 number of aberrant Asiatic voles, and, as with Antheliomys 

 and Eothenomys^ the exact value that should be given to it is 

 by no means clear. While it has the rounded skull, round- 

 angled teeth, and external form of true Evotomys, it has the 

 encapsuled ?n^ and w?.^ of Craseomys, Antheliomys, and normal 



* 0avXo£'= weak. 



