150 Mr. O. Thomas an ' 



liut size, as gano;ed by skull, averaging slightly largei'. 

 Oolour paler, the Hanks t specially paler and more hoary grey, 

 and the tail sfeneially more or less whitened beneath in its 

 terminal half. In true longicaudatus the tail is uniformly 

 brown throughout. 



Dimensions of no. 84!) (type), measured in the flesh : — 



Head and body 158 mm. ; tail 225 ; hind foot 32 ; 

 ear 20. 



Skull : frreatest length 3y'2 ; condylo-incisive length 35*4 ; 

 zygomatic br^ a 1th 18*4 ; nasals 15; interorbital breadth 5*6 ; 

 palatal foramina 7'5 ; upper molar series G*5. 



Locali/ies. Medje, Upper Ituri (type) ; Pili(nli (Makala), 

 Ituri ; Fundi, Itud ; and Poko, Upper Welle. Twelve 

 specimens examined. 



GrammOMYS, gen. nov. 



Like Thoinnpmys, but the postero-internal or ".r" cusp nf 

 the first and second molars reduced to a mere connecting- 

 lidge running from the inner cusp of the median lamina to 

 the hinder point of the tooth. 



External characters as in Thamnomys. 



Type. Grammomys dolichurus (^Mus doHchurus, Smuts). 



\Vlien originally founding the genus Thamnomys, I pointed 

 out that it contained two groups of species: (1) the typical 

 Thaiti7iomys, with the cusp x strongly developed, and 

 (2) those more or less intermediate between Thamnomys and 

 Epimys, in which this cusp was reduced to a narrow ridge, 

 often hardly perceptible. 



With tire great increase in the number of known species, I 

 now think it advi.-able that this intermediate group should 

 iiave a special name. 



To Thamnomys proper there only belong the following 

 forujs : — veuustns (type), ruttlans^ Icuru, and kempi ; while 

 there go into. Grammomys tlie great mass of the known 

 species, including dolic/iuius, surda.der, riiddi, balioliis, bun- 

 tinyi, ibeanus, macmiUani, conieUs, d scobjr, g'ffaSy dryas, and 

 a few others described as subspecies of these. 



Deomys christyij sp. n. 



Size about the ?anie as in D.ferruglnevs. General colour 

 above paler and more drabby ; the ground-colour along the 



he naturally considered the name longicaudatus given by TuUberg as ante- 

 dnted by Bennett's Mus longicaudatus from S. Anr-ica. But now that 

 these rats are no longer placed in Mus, Tullberg'.-, iiame, given in con- 

 junction with tlie incorrect generic term Dasymy^, becomes again avail- 

 able for the Cameroons form. 



