% 



NO. 2188. MAMMALS FROM ISLANDS OFF SUMATRA—LYON. 451 



Geographic distribution. — Maiisalar Island. 



Diagnostic characters. — ^A dull colored member of the Rattus vocif- 

 erans gi'oup, with the general color avellaneous, replacing the cinna- 

 mon-buff of Rattus vociferans tapanuUus; ^ skull angular with thick, 

 heavy rostrum, as compared with R. fremens fremens. 



Color, etc. — Upperparts and sides of head, neck, and body, and 

 outerside of legs a mixture of dull ciimamon-buff and blackish; the 

 darker color predommating along the middle line of head and back, 

 the two about equally mixed along the sides and outerside of legs 

 producing the general effect of avellaneous. Underparts mcluding 

 innerside of legs, varying from wliitish to cream color. Tail, dull 

 brownish, somewhat hghter on miderside at base. Eight scales to 

 the centimeter at center, each scale subtended by three light colored 

 hairs about one and one-half scales in length. 



SJcull and teeth. — Skull, in comparison with Rattus vociferans tapanu- 

 Uus &nd fremens fremens, large, angular, heavy, particidarly rostrum; 

 temporal ridge beading well marked and angle of beadmg at fronto- 

 parietal suture conspicuous. Teeth show no essential differences 

 from related members of the gi'oup. 



Measurements. — Type: Head and body, 250 mm.; tail, 299; hmd- 

 foot, 47; condylobasal length, 51.5; zygomatic width, 25.5; width of 

 braincase, 20; maxillary toothrow, 10.5. Tail rather short for the 

 group; about 300 mm. or sUghtly less. 



Specimens examined. — Seven from Mansalar Island. 



RemarTcs. — In spite of the close proximity of this form to Rattus 

 vociferans tapanulius of the adjacent mainland it is very closely re- 

 lated to Epimys fremens fremens Miller- of Smkep Island, in its gen- 

 eral characteristics. It is probably a case of jDarallel development. 



RATTUS FREMENS TUANCUS, new subspecies. 



1903. Mm fremens Miller, Proc. U. S. Nat. Mus., vol. 26, p. 463, February 3, 

 1903. 



Type-Specimen. — No. 114402, U.S.N.M., skin and skull of adult 

 male, collected on Pulo Tuanku, Banjak Islands, January 26, 1902, 

 by Dr. W. L. Abbott; original number, 1470. 



Geographic distribution. — Pulos Tuanku and Bankaru, Banjak 

 Islands. 



Diagnostic characters. — A dull colored member of the Rattus vocif- 

 erans group very similar to R. fremens mansalaris above, but skull 

 slenderer, less angidar, with longer, slenderer rostrum, and differing 

 from R. fremens fremens in its larger size of skull and relatively shorter 

 tail, 



1 Lyon, Proc. Biol. Soc. Wash., vol. 29, p. 209, September 22, 1916. 



2 Proc. Acad. Nat. Sci. Philadelphia, 1902, p. 154, March, 1C02. 



