Ml-. O. Tlionins on African Rodents. 223 



In E:\>;t Africa tlio type of L. le^tud )^ Tlios.,was obtained 

 by Mr. F. J, Ja-k.HOii at ll.ivinc Station, and other speci- 

 nieiis have since been referred to it. Hut now examination 



1)rove8 that the typo remains unique, and that all the other 

 0. African specimens avaihible belong to a larger species 

 closely allied to the Abyssinian one and itself divisible into 

 two subspecies. 



Subjoined are the diagnostic characters of the four species 

 which at present appear to be recognizable. 



In drawing them up I have had for examination two 

 specimens of Z>. t'mhaiisif two of L.hozasi (including one skull 

 bi longing to the United States National Museum), six of 

 L. ilnanus (including a U.S.N.M. skull tVom Nakuru), and 

 one — the type — of L. teshulo. 



Size comparatiTolv Urge. Frontal region con- 

 cave. Mesoptery^'oid fo.«sn long. Ante- 

 orbital foramen high, narrow, slit-like. Pala- 

 tal foriimina long. Sides of prenia-xillse not 

 or scarcely granulated, except along the edge 

 bordering the nasals. (Abyssinia.) 



L. bvzasi, Oust, (probably L. cpthiopicus, Peters). 

 Size variable. Frontal region more normal. 

 Mesopterygoid fossa long. Anteorbital fora- 

 men larger and more open ; its outer edge 

 thickened into a ridge, with a large masse- 

 teric knob at its lower end. Palatal foramina 

 shorter. Sides of premaxillaj heavily granu- 

 lated, especially in the fossa just above the 



incisors. (British E. Africa.) L. iheanm, .<;p. n. 



Size and teeth smaller. (Mau Region. ) L. ihetmns ibeanun. 



Size and teeth larger. (Aberdaro Range.) L. i. hi/idei, subsp. u. 



Size smaller. Me.sopterygoid fossa very short. 

 Anteorbital foramen very small, low, well 

 open, its outer edge practically without 

 strongly marked ridge or masseteric knob, 

 Ka.*als markedly narrowed in their posterior 

 lialf, parallel-sided in all the other forms. 

 Incisors narrow, dead white in front, crt>am- 

 roloured in other species. Line of glandular 

 bustles on sides narrower and Itss con- 

 s])icuous than in other species. (British E. 



Africa.) L. testti-Jo, Thos. 



Size smallest. Mesopterygoid fossa long. Ante- 

 orbital foramen comparatively large, well 

 open, its edge ridged and with well-marked 

 ma<vetvric knob. Frontal region promi- 

 nently white, grey in the other species. 

 (Sumali-land.) .... Z. hnhausi, .M.-Edw. (syn. L. smithi, Rhoads). 



The following are the chief diagnostic measurements of 



the skulls : — 



