NO. 1317. MAMMALS OF NORTHWEST SUMATRA— MILLER. 



459 



head and body, Sol; tail vertebrae, 198; hind foot, 42.4 (40). Avcr- 

 ag-c of 5 adults from the type locality: Total length, 388 (877-402); 

 head and body, 200 (200-218); tail vertebrae, 182 (176-198); hind foot,' 

 40.4 (39.2-42.2); hind foot Avithout claws, 37.8 (36-40). For details, 

 see table, page 459. 



Cranial measurements of type: Greatest length, 47.4 (46) ;« basal 

 length, 41.8 (40); basilar length, 89 (37); diastema, 13 (12.4); length 

 of incisive foramen, 9 (8); combined breadth of incisive foramina, 3.4 

 (3.8); length of nasals, 18 (17.6); greatest breadth of ])oth nasals 

 together, ,5.2 (5.6); zygomatic breadth, 23 (22); least interorbital 

 breadth, 7.4 (7); breadth of brain case above roots of Z3^gomata, 17 

 (17); depth of brain case at front of basioccipital, 12(11.4); fronto- 

 palatal depth at posterior extremity of nasals, 11.8 (11.6); mandible, 

 28 (28); maxillary tooth row (alveoli), 8 (8.4), mandibular tooth row 

 (alveoli), 8 (8.4). 



Specimens exmnined. — Thirt3'-two from the following localities: 

 Simalur Island (main island), 8 (2 in alcohol); Simalur Island (Pulo 

 Siumat), 6 (1 skull without skin); Pulo Lasia, 16 (3 in alcohol; 3 

 skulls without skins); Pulo Babi, 2 (skulls only). 



Remarks. — This is a well-defined memljer of the Ifus rattus group, 

 most closely related, apparently, to the form occurring on the Butang 

 Islands on the opposite side of Sumatra. Its presence on Simalur and 

 the neighboring islands may have been originally due to human 

 agency, though there is no reason to suppose that the animal has been 

 introduced within historic times. 



Measurements of Mus simalurensis. 



Locality. 



Sex. 



Hind 

 foot 



with- 

 out 



claws. 



Simalur Island 



Do 



Do 



Do 



Dio 



Do 



Pulo Siunuit... 



Do 



Do 



Do 



Do 



Pulo Lasia 



Do 



Do 



Do 



Do 



Do 



Do 



Do 



Do 



114214 

 114215 

 114213 

 a 114216 

 114217 

 114218 

 114221 

 114225 

 114222 

 114223 

 114224 

 114257 

 114260 

 114261 

 114262 

 114253 

 114254 

 114255 

 114256 

 114268 



Male adult 



do 



Female young 



Female adult 



do 



do 



Male adult 



do 



Female adult 



Female young 



Female adult 



Male adult 



do 



do 



Male young 



Female young 



Female adult 



do 



Female young 



Female adult 



"Type. 



mm. 

 36 

 36 

 35 

 40 

 38 

 39 

 38.6 

 40 

 88 

 37 

 38.4 

 39.4 

 39 

 40 

 40 

 38 

 40 

 39 

 39 

 41.2 



"Measurements in parentheses are tliose of an adult lemale Mus pannosus (No. 

 10411.5) from Pulo Adang, Butang Islands. 



