136 BULLETIN 99, UNITED STATES NATIONAL MUSEUM. 



Specimens. — Thirty-four, from localities as follows: 

 British East Africa: Archer's Post, 6, including 1 in alcohol 

 (Heller) ; Isiola River, 7, including 2 in alcohol (Heller) ; Lakiundu 

 River, 14, including 1 in alcohol (Heller) ; Lorian Swamp, 2 (Percival) ; 

 Mount Lololokwi, 1 (Heller); Northern Guaso Nyiro River, 1 in 

 alcohol (Cuninghame) ; Orr Valley, Mount Nyiro, 2 (Percival) ; 

 South of Mount N3dro, 1 (Percival). 



This small species is found in the same localities with the much 

 larger ArvicantJiis ahyssinicus chanleri, but the difference in the size 

 of the skulls is so great that there should be no confusion in deter- 

 mining specimens. 



Genus LEMNISCOMYS Trouessart. 



1881. Lcmniscomys Trouessart, Bull. Soc. Scient. Angers, vol. 10, pt. 2, p. 124. 



(L. barbarus.) 

 1912. Lcmniscomys TIeller, Smithsonian Misc. Coll., vol. 59. No. 16, pp. 11-12. 



Julys. (Part.) 

 1916. Lcmniscomys Thomas, Ann. and Mag. Nat. Hist., ser, 8, vol. 18, pp. 68-69. 



July. 



This genus of striped grass rats as recognized by Thomas includes 

 those species of the old genus ArvicantJiis which have the fifth finger 

 much shortened, with a nail instead of a claw. The East African 

 species belong to three distinct groups. The griselda (dorsalis) group 

 includes forms distinctly marked by a single median dorsal stripe. 

 The forms of the striatus (jmlcJiellus) group are marked by numerous 

 rows of fight spots, frequently blended. In the last group, including 

 subspecies of harbarus, there are numerous uninterrupted fines run- 

 ning lengthwise over the entire upperparts. 



LEMNISCOMYS GRISELDA MACULOSUS (Osgood). 



1910. ArvicantJiis dorsalis maculosus Osoood, Field Mus. Zool. ser., vol. 10, No. 3> 



p. 17. April 7. (Voi, British East Africa; type in Field Mus. Nat. Hist., 



Chicago.) 

 1910. Arvicanlhis dorsalis maculosus Roosevelt, African Game Trails, Amer. ed., 



p. 473; London, ed., p. 485. 

 1910. Arvicanlhis dorsalis phxotis Thomas, Ann. and Mag. Nat. Hist., ser. 8, vol. 



6, p. 429. October. (Mazeras, British East Africa; type in British 



Museum.) 



Speciinens. — Twenty-seven, from the foUowing localities:. 



British East Africa: Changamwe, 15, including 8 in alcohol 

 (Mearns); Maji-ya-chumvi, 2 (Hefier); Mount Mbololo, 5 (HeUer); 

 Mount SagaUa, 3 (HeUer) ; Mtoto Andei, 2 (HeUer). 



The differences given by Thomas in separating the Mazeras sub- 

 species from maculosus prove to be too slight and too inconstant to 

 warrant the recognition of a form from this region. The grayest 

 specimens in our coast series are all rather young animals with the 



