146 BULLETIN 99, UNITED STATES NATIONAL MUSEUM. 



LEMNISCOMYS BARBARUS CONVICTUS (Osgood). 



1910. Arvicanthis barbarus convictus Osgood, Field Mus. Zool. ser., vol. 10, No. 

 2, p. 10. February. (Voi, British East Africa; type in Field Mus. Nat. 

 Hist., Chicago.) 



Specimens. — Five, including 1 in alcohol, as follows : 

 British East Africa: Mtoto Andei (Heller). 



Genus RHABDOMYS Thomas. 



1916. Rhabdomys Thomas, Ann. and Mag. Nat. Hist., ser. 8, vol. 18, p. 69. July. 

 (R. pumilio.) 



The group of species of the old genus Arvicanthis including pumilio 

 and its allies has been recognized by Thomas as a distinct genus. 

 The forms all have four dark stripes on the back and a normal fifth 

 fiinger with claw. 



RHABDOMYS PUMIUO DIMINUTUS (Thomas). 



1892. Isomys pumilio diminutus Thomas, Proc. Zool. Soc. London, 1892, p. 551. 



(Mianzini, east of Lake Naivasha, British East Africa; type in British 



Museum.) 

 1910. Arvicanthis pumilio diminutus Roosevelt, African Game Trails, Amer. 



ed., pp. 473 and 479; London ed., pp. 485 and 490. 



Specimens. — Eighty-seven, from localities as follows: 

 British East Africa: Aberdare Mountains, 7, including 1 in 

 alcohol (Heller); Guas Ngishu Plateau, 30 miles north of Ravine, 5, 

 including 2 in alcohol (Heller); Laikipia, 1 in alcohol (Heller); 

 Mount Kenia, 19, includmg 4 in alcohol (Loring, Mearns); Naivasha 

 Station, 28, including 2 in alcohol (Loring); Nyeri, 27, including 4 

 in alcohol (Loring). 



Loring found two females each with five large fetuses at Nyeri, 

 September 16; and one at the same place, September 17, with three 

 fetuses. Most of the Mount Kenia specimens are from the West 

 Kenia Forest Station at 7,500 feet altitude, but Doctor Mearns 

 caught one specimen at 10,000 feet on Kenia, and Heller found the 

 species common on the summit of the Aberdare Range. Specimens 

 from Nyeri and Mount Kenia average slightly more reddish than the 

 Naivasha skins, but the difference is insignificant and may be sea- 

 sonal, as the Naivasha specimens were collected in July and early 

 August while the Kenia material was taken in September and Octo- 

 ber. For measurements see page 145. 



Genus OTOMYS Cuvier. 



1823. Otomys Cuvier, Dents Mamm., p. 168. (0. irroratus.) 



1831. Otomis Bonaparte, Giorn. Arcad. di Sci. Lett. Art., Roma, vol. 53, p. 193. 

 1918. Otomys Thomas, Ann. and Mag. Nat. Hist., ser. 9, vol. 2, p. 207. Sep- 

 tember. (Revision of superspecific groups.) 



In listing the swamp rats in the collection I have followed the ar- 

 rangement of Dollman,^ which seems quite satisfactory so far as our 



1 On the Swamp-Rats {Otomys) ol East Africa, Ann. and Mag. Nat. Hist., ser. 8, vol. 15, pp. 149-170. 

 January, 1915. 



