6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 56 



Characters. — Long snouted like soreUus, but snout longer, the 

 nasal bones measuring 8.5 mm. in length ; upper parts much lighter, 

 ochraceous-buff. 



Coloration. — Median dorsal region from eyes to base of tail ochra- 

 ceous-buff, heavily lined with black; snout and sides of head and 

 body from level of eyes purer ochraceous-buff, changing to fulvous 

 on lower sides where this color meets the white of the under parts. 

 Ears hair brown, an ill-defined white spot at their base. Tail nearly 

 naked ; light brownish above, whitish below. Under parts, feet, 

 and snout from level of nose, white ; the hair white to the roots. 



Measurements. — Head and body, 68 mm.; tail, 40; foot, 15. 

 Skull: occipito-incisive (greatest) length, 20.5; condylo-incisive 

 length, 20; length of nasals, 8.5; width of interorbital constriction, 

 3.2; length of palatal foramina, 5.4; width of brain case, 9; length 

 of upper molar series, 3.6. 



This species is closely allied to sorellus, with which it agrees in 

 the peculiar elongate snout and straight projecting incisors, and 

 also in general proportions of body. Sorellus is, however, only 

 distantly related to grains, but shows close relationship to tenellus 

 in the formation of the short, narrowed mesopterygoid region, 

 straight incisors and short tail. The group to which this species 

 belongs represents the extreme divergence of the African Leggadas 

 from the Mus musculus group in skull characters. This differ- 

 ence from the type species of Mus is most marked in the straight, 

 projecting incisors, the elongate snout, the abbreviated, narrow, 

 mesopterygoid fossa, and the minute coronoid process of the man- 

 dible. In the two latter characters these long-snouted African Mus 

 approach somewhat the skull condition exhibited by Acomys. 



This is rather a rare species, being represented by only one skin 

 and one alcoholic specimen in the collection, which contains some 

 hundred specimens of Leggadas from British East Africa. 



MUS TENELLUS ACHOLI, new subspecies 



LoNc-sNouTED Pycmy Mouse 



Type from Rhino Camp, Lado Enclave; adult male, number 

 164817, U. S. Nat. Mus.; collected by J. Alden Loring, January 13, 

 1910; original number, 8671. 



Characters. — Coloration of tenellus, but size much larger, with 

 large skull and proportionately short tail. 



Co/ora^ioM.— Median dorsal area mixed blackish and fulvous, the 



