140 MR. OLDFIELU THOMAS OX 



Size rather smaller than in 21. (E.) vielanogaster. General 

 colour a less warm brown than in that animal, the upper surface 

 nearest to "sepia"; under surface dark slaty grey (rather moi-e 

 smoky than " grey no. 5 ''). Hands and feet brown, soles with 

 6 pads. Tail dark brown above, little lighter below. 



Skull rather smaller than that of M. melanog aster, but similar 

 to it in general form ; the bullae not quite so large. 



Teeth agreeing with those of melanogaster in the junction to 

 each other of nearly all the opposite spaces of the teeth, and 

 therefore equally differing from the members, now four in number, 

 of the subgenus Caryomys. But they are readily distinguished 

 by the fact that ni^ has not got the characteristic supplementary 

 postero-internal salient projection occurring in both m^ and m'^ 

 of melanogaster, and here present of full size in m" ; as a result, 

 there are three internal angles on both these teeth. M* more 

 complicated than in tnelanog aster, with four salient angles on each 

 side \ it consists of three sepaiated dentine spaces, the first with 

 one inner and two outer angles, the middle one with one external 

 and one intenial angle, and the posterior with two internal and 

 one antero- external angle. Lower teeth essentially as in melano- 

 gaster, the spaces all opposite and united. 



Dimensions of the type, measured in the flesh : — 



Head and body 82 mm.. ; tail 34 ; hind foot 16 ; ear 9. 



Skull: condylo-incisive length 24; zygomatic breadth 15"4 ; 

 nasals 6"8 ; interorbital breadth 4 ; height of crown from alveolus 

 of m^ 7'5 ; bi-eadth of brain-case 11; palatilar length 11"5 ; palatal 

 fora,mina 4*7 ; upper molar series (crowns) 5'5. 



Hab. as above. 



7V^e. Adult female. B.M. No. 11.9.8.122. Original number 

 2714. Collected 19 March, 1911. 



The dentition of this Vole is interesting, as it confoi-ms strictly 

 to the Eothenomys as opposed to the Caryomys type, while pie- 

 senting such differences from that of M. (^E.) melaQwgaster as 

 readily to distinguish the two species. 



*' Trapped in the open fields of the little cultivated plain sur- 

 rounding the city." — M. P. A. 



28. MiCROTus (Caryomys) alcinous. 



Thos. Abstr. P. Z. S. 1911, p. 50 (Oct. 31). 



c? . 2609, 2611, 2612, 2617, 2618, 2620, 2628, 2629, 2630, 2631, 

 2633, 2634. $ . 2619. Wei-choe, Si-ho E., W. Sze-chwan. 

 8000-12,000'. 



Essential characters as in M. (C.) eva, but colour much dai'ker. 



Proportions, skull, and teeth all abovit as in eva. Fiu- long 

 and soft ; hairs of back about 9-10 mm. in length (winter), 

 (ieneral colour above uniform dark bistre-brown, conspicuously 

 different fiom the pale brown M, eva ; under surface dark 

 smoky grey, decidedly darker than Ridgway's "smoke-grey." 

 Ears aljout as long as the fnv, their backs with some whitish 



