lo The Hatvaiian Rat. 



does, however, seem extremely unlikely that islands, as far removed 

 as Tahiti and Fiji, should have possessed animals identical with 

 those of Hawaii. Therefore it would seem desirable to name the 

 Hawaiian native rat as a distinct species and a description of it 

 is here appended. It may be known as : 



Rattus ' hawaiiensis. 



(Plate VIII.) 



Type. No. 9010, Colin. Bernice Pauahi Bishop Museum. 

 Popoia Island, Oahu, Hawaiian Islands, $ . May 9, 1915. 



Description. Above cinnamon brown or russet shading into 

 cinnamon buff on the sides and light buff or buffy white below, 

 strongly mixed with black hairs on the back and sides. Feet nearly 

 white above, the dusky color of the legs overspreading the tarsus 

 and carpus and narrowing to a point. Whole underside of the 

 hind feet dark. 



Measurements . Length, 239 mm.; tail, i iS; hind foot, 26; ear, 9. 



Skull. Length (occipito-nasal). 32 mm.; zygomatic breadth, 

 16; interorbital breadth, 5.5; basilar length of Hensel, 27.5; molar 

 tooth row, 5.5; median length of nasals, 12; total length of man- 

 dible, 22. 



A female (No. 9012, Colin. Bernice Pauahi Bishop Museum), 

 now in the collection of the Academy of Natural Sciences of Phila- 

 delphia, is exactly similar in coloration but slightly smaller in size. 



IMeasurcments. Length, 225mm.; tail, iii; hindfoot, 25; ear, 9. 



Skull. Length (occipito-nasal), 31 mm.; zygomatic breadth, 

 16; interorbital breadth, 5.3; basilar length of Hensel, 25; molar 

 tooth row, 5.5; median length of nasals, 11; total length of 

 mandible, 21. 



In concluding the account of this interesting rodent, I wish to 

 acknowledge the kindness of Mr. J. F. G. Stokes in placing all of 

 his material and notes in my hands for description. The paper is 

 really more his than mine, and to his indefatigable efforts we are 

 indebted for bringing to light this animal long since regarded as 

 extinct, 



'The Hawaiian Rat is placed in the genus Rattus as opposed to Mus (type 

 M. musculus), following Trouessart. It may be that the old genus Mus is 

 susceptible of further generic subdivision and that this species is not con- 

 generic with the Norway and Black Rats. 



[260] 



