On the Swamp-Rats of East Africa. 1-49 



References. 



P. P. C. HoKK. " Pycnogonida," ScieiitiKc Results of the Vo3'age of 



11. M.S. 'Chiilleuger,' 187y-7().— Zoology, vol. iii. 1881. 

 K. MoBius. " Die Pantopodeii," Wiss. Ergebu. d. Tielsee Ex. * Valdivia/ 



Bd.iii. pp. 178-196. 

 T. V. IIoDGSox. " On a uew Pycnogoiiidfrora tlieSoiith Polar Regions," 



Ami. & Mag. Nat. UUt. (7) vol. xiv. p. 4o8. ll>04. 

 E. BouviER. ' Pycuogouides du Fiau^ais E.Kped. antarct. frannaise.' 



1906. 

 T. V. Hodgson. " Pycnogonida," Voyage of the ' Discovery.' — Natural 



History, vol. iii. 1907. 

 . " Pycuogouida of the Scottish National Antarctic Expedition," 



Trans. Rov. Soc. Ediu. vol. xlvi. pp. 159-188. 1908. 

 J. C. C. LoMAN. " Die Pantopoden du ' Siboga ' Expedition," ' Siboga' 



Expeditie, Monog. xl. 1908. 

 E. BooviicR. " Pycnogonides du * Pourquoi Pas,' " Deuxieuie Exped. 



autarct. fran9aise. 1912. 



IX. — On the Swamp- Rats (Otomys) of East Africa. 

 By Guy Dollman. 



(Published by permission of the Trustees of the British Museum.) 



In the following revision of tlie Eust-Africaii swamp-rats it 

 lias been found necessary to modify considerably tlie arran<^e- 

 ment adopted by Wroiighton in bis 1906 paj)er *. Tlie 

 forms tropicali's, nijikce, angoniens'is, orestes, and denti are 

 here raised to full specific rank, tropicilis taking tbe place of 

 irroratus, wbicli species, on account of its cranial structure 

 and lamina formula, is not considered a near enough relative 

 for the name to be used in connection witb the East-African 

 forms; in this manner we confine z'/vora^Ms and its subspecies 

 to the country south of the Zambesi. As subspecies of 

 tropicalis we then have elgonis and two new forms from the 

 Jombeni Hills and Mt. Nyiro. In this paper descriptions 

 are given of seven new Otomijs, all from British East Africa 

 and Uganda. 



Ken ^^ ^^'^ Species and Subspecies. 



A. Lower incisors with one deep groove. 

 Ventral surface of tail dark. 

 a. vi^ with 5 lamiuie. (Ruwenzori East.) (1) denti, Thos. 



* Ann. & Mag. Nat. Tlist. (7) vol. xviii. p. 264 (1906). 



