A SUB-DIVISION OF THE OLD GENUS NESOKIA. 467 



Both Dr. Cantor in 1845, and Capt. Flower half a century later obtained in 

 the little island of Pin an g examples representing two species of this genus, a 

 large and a small. The former marked both his • specimens as " Mas setifer " 

 evidently taking them for the same species, but there cannot be the slightest 

 doubt that they are quite distinct animals, their difference in size being far 

 too great to be due to individual variation. 



MUS ROGERSI, sp. n. 



A spinous-haired species with 1-3 = 8 mammae. 



Size of Mas norvegicus. Fur coarse, profusely mixed with spines, which on 

 the back are about 16 mm. in length by 0*4 mm. in breadth. General colour 

 coarsely grizzled ochraceous brown, the bases of both hairs and spines pale grey 

 and tips of the spines black and of the ordinary hairs ochraceous. The few 

 long bristle-hairs are wholly black. Sides greyer. Under surface not sharply 

 defined, pale buffy greyish, the hairs pale slaty at base, dull cream-buff termi- 

 nally. Ears finely haired, dark grey. Limbs dark grey externally, light grey 

 like belly along their inner aspect. Hands and feet white above, the metapodi- 

 als slightly darker ; fifth hind toe, without claw, reaching to the end of the 

 first phalanx of the fourth. Tail rather shorter than head and body, almost 

 naked ; rings of scales about 10 to the centimetre ; dark brown above, whitish 

 flesh-colour below. Mammas 1-3 = 8. 



Skull strongly built, with well marked supraorbital beads, which are conti- 

 nued across the parietals to the corners of the interparietals. Muzzle rather 

 narrow, parallel-sided. Palatal foramina not reaching back to the level of the 

 molars. Mesopterygoid fossa broadly rounded in front, its anterior limb slight- 

 ly anterior to the front end of the parapterygoid fossa? on each side of it. 

 Bulla? of medium size. Molars small in proportion to the general size. 



Dimensions of the type (measured on the spirit-specimen before skin- 

 ning) :— 



Head and body 195 mm. ; tail 188 ; hind foot ( s. u. ) 41 ; ear 28. 



Skull, greatest length 48-5 ; basilar length 40 ; zygomatic breadth 22*5 ; nasals 

 18 x 5 ; interorbital breadth 7*2 ; greatest separation of parietal ridges 16 ; 

 palatilar length 23*3 ; diastema 14*2 ; palatal foramina 9*2 ; length of upper 

 molar series 7*8. 



Habitat. — W. Coast of South Andaman Island, north of Ike Bay. 



Type— Adult female. B. M. No. 6.4.13.2. Collected February 1904, and pre- 

 sented by'.C. G. Rogers, Esq. 



In spite of the number of rats recently described by Mr. G. S. Miller* from 

 the Andaman group, this fine species does not appear to have been previously 

 obtained. Its unusual mammary formula, 1-3 = 8, is alone shared, in the 

 whole of the Muridae, by Mm bagobus, Mearns, from the Philippines, and Mas 

 pulliventer, Miller, from the Nicobars, of which latter it may be the Andaman 

 representative, but from which it differs by its markedly larger size and distinct- 

 ly bicolor tail. 



* Pr. U. S. Nat Mus XXIV, p. 758 (Synopsis of species) (1902). 

 81 



