3 68 



Dr. F. A. JENTINK. MAMMALS. 



ner that the anterior broadened ridges are rather deeply curved ; this curvity diminishing in 

 the follovving ridges, so that the posterior or hindmost ridge is straight as I already mentio- 

 ned. I hope that this description may give a rather good impression of the remarkable com- 

 plicated structure of thèse interdental ridges; fig. 6 may aid in unravel the thing. As I re- 

 marked we only possess a single young maie to base the description upon, therefore it may 

 be that more material will give rise to separate our animal generically from Pogonomys, but 

 for the présent I think that a prématuré new genus-name serves no useful purpose. 

 Some measurements of the skull : 



mM. 

 occiput to anterior margin of nasalia .... 48 



distance between eyeholes 9 



canthus to anterior margin of nasalia .... 17 



upper molar séries (2 molars!) 9.5 



diastema 13 



11. Mus rattus Linné. 

 Of this fine omniprésent animal there is in the Humboldt Bay expéditions' collection a 

 single young adult maie, collected on the Sentani Lake, Humboldt Bay, April 7. 1903. 



12. Mus Browni Alston. 



2 maies, 2 females, from Sentani Lake, 7 and 8 April and 3 June. 



4 maies, 7 females, from Metu Debi, 27 April and 2 May. 

 6 maies, 9 females, from Tobadi, 2.9 and 30 April. 



5 maies, 4 females, from Ingras, 4 May. 



(?) 2 very young spécimens, from Manokwari, 21 May and 30 June. 



2 maies, 1 female, from Mawes, 12 June. 



3 maies, 4 females, from Wendèsi, 30 July. 

 (?) 2 very young spécimens, from Merauke. 



I compared thèse individuals with two maies and two females, collected by Mr. Loria 

 in September 1880 at Aroma, British New Guinea, kindly presented to our collection by 

 Dr. GESTRO from the Genoa Muséum, and with Alston's description of the type-specimens 

 (P. Z. S. L. 1877, p. 124), and I fail to detect any important différence, although there seems 

 to be a very great variation in length of the tail; hère are some measurements in millimeters : 





head 



md body 



tail. 



ear. 



hindfoc 



Sentani Lake 



cT 



15° 





16 



27-5 





9 



140 





16 



27 



Metu Debi. 



& 



145 



127 



16 



27 





cT 



z 35 



137 



16 



28 





cT 



i°5 



116 



16 



26 



Tobadi. 



c? 



156 



147 



16 



28 





9 



140 



137 



16 



25-5 



Ingrâs. 



c? 



162 



15° 



17 



28 





c? 



15° 



ïS 1 



17 



28 



Mawes. 



c? 



125 



124 



IS 



26 



Wendèsi. 



c? 



i37 



15° 



17 



29 





c? 



135 



137 



16 



27 





9 



15° 



140 



17 



27 





9 



114 



122 



14 



25 



