1905.] MAMMALS FROM JAPAN. 349 



cJ . 373, 374. 2 ■ 375, 376. Kuma, Eliime Ken, Shikoku. 

 1200'. 



J. 459, 460, 461. $. 452. Kawachi, Miyasaki Ken, Kiu- 

 shiu. 1500'. 



6 . 390, 391, 402, 411, 412, 425, 436, 437. $ . 393,^ 418, 419 

 426, 433. Takamori, Kumamoto Ken, Kivishiu. 1850'. 



c? . 483, 498, 499. 5 . 484, 491. Tano, Miyasaki Ken, Kiu- 

 shiu. 500'. 



" Common everywhere." 



Even with this fine series, combined with that sent by 

 Mr. Gordon Smith, I am unable to trace completely the relation 

 of the presence of spines in the fur to season and sex. Many 

 specimens of each sex are spinous, many spineless, and in a general 

 way it is clear that spines are a character of summer, while they 

 are rarely or never present in the winter pelage. Two examples, 

 however, killed in the middle of December have spines, and one 

 from Shikoku, killed in February, so that there are evidently 

 exceptions to the general rule. 



Young specimens, before the development of the rufous colour, 

 are always spineless. 



The mammary formula in this species is 2 — 2 = 8. 



It appears probable that Temminck's Mus argenteus, also 

 described in the ' Fauna Japonica,' was based on small spineless 

 specimens of 21. sjMciosus. 



The following are the dimensions (in mm.) of a pair fi'om the 

 Izu peninsula : — 



c? . Head and body 128 ; tail 112 ; hind foot 24 ; ear 16. 



?. „ „ 115; „ 105; „ 24; „ 15. 



30. MiCROMYS SPECiosus AiKu, subsp. n. 



S • 10. Jozankei, near Sapporo, Hokkaido. 



2 • 26. Shinshinotsu, near Sapporo, Hokkaido. 



2- 108, 117. Aoyama, Hokkaido. 



As in true sjieciosus, but with rather longer feet and longer 

 skull. 



General characters as in the M. speciosus of Hondo, with the 

 same dark fulvous colour blackened along the dorsal area and the 

 same whitish underside. Fur similarly either spinous or spine- 

 less. Hands and feet greyish white. Feet longer and heavier 

 than in true S'jyeciosus. 



Skull rather narrower and more elongate than in true speciosus ; 

 palatal foramina longer. 



Dimensions of the type, measured in the flesh : — 



Head and body 118 mm. ; tail 107 ; hind foot 27*5 ; ear 15. 



Skull — greatest length 31; basilar length 25; nasals 12 '2; 

 interorbital breadth 4*8; breadth of brain-case 12*8; palatilar 

 length 14-4; diastema 9*5; palatal foramina 5' 8 ; length of upper 

 molar series 4" 2. 



Hah. Hokkaido. Type from Aoyama. 



