788 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XIV. 



Mammce. — There are 10 mammae, 2 pectoral and 3 inguinal on each side. 



I^tet. — The feet are in no way peculiar. Soles naked, with 6 well-deve- 

 loped tubercles. 



Ears. — The ears are essentially as in Mus stoicus. 



Skull. — The skull of 3ius fiebiUs resembles that of the larger members of 

 the Mus rattus group, but is readily distinguishable by its larger audital bullas 

 and more strongly developed supraorbital ridges. In the latter character 

 it suggests Mus surifer and its allies. As compared with the skull of Mus 

 pannosus tliat of Mus flebiUs differs, aside from the characters just men- 

 tioned, in slightly smaller size, relatively shorter, more robust rostrum, 

 narrower outer wall of antorbital foramen, more abruptly flaring zygomata, 

 and longer incisive foramina. The mandible is essentially the same in both 

 species. Its much greater size (greatest length about 45 mm. instead of 

 about 40) immediately distinguishes the skull of Mus fieUlis from that of 

 Mus rattus and Mus alexandrinus. 



Teeth. — The teeth exactly resemble those of Mus alexandrinus and Mas 

 rattus in form and in pattern of enamel folding, but are conspicuously larger. 

 In the latter character they are slightly surpassed by those of Mus pannosus. 



Measurements. — External measurements of type : Total length, 452 mm ; 

 head and body, 210 ; tail, 242 ; hind foot,41"4 ; ear from meatus, 21 ; ear from 

 crown, 16 ; width of ear, 15. Average of six adults from the type locality ; 

 Total length, 441 (417— 460) ; head and body, 203; tail, 238 (222—240): 

 hind foot, 41-8 (41—44) ; hind foot without claws, 40 (39—42). 



Cranial measurements of type : Greatest length, 45 mm. ; basal length, 

 40; basilar length, 37; palatal length, 21*4; least width of palate between 

 anterior molars, 5 ; diastema, 13 ; length of incisive foramen, 8'8 ; combined 

 breadth of incisive foramina, 3 ; length of nasals, 18 ; combined breadth of 

 nasals, 4"8 ; zygomatic breadth, 19'8 ; interorbital breadth, 6 ; mastoid 

 breadth, 18; breadth of braincase above roots of zygomata, 16; depth of 

 braincase at anterior border of basioccipital, 11 '4 ; fronto-palatal depth at 

 posterior extremity of nasals, 11 ; least depth of rostrum immediately behind 

 incisors, 8'S ; mandible, 26 ; maxillary toothrow (alveoli), 7*4 ; width of front 

 upper molar, 2'2; mandibular toothrow (alveoli), 7'4. 



Specimens examined. — Seven, all from the type locality. 



Remarks. — These rats were trapped, together with the specimens of Mus 

 stoicus, in the dense jungle with which Henry Lawrence Island is covered. 

 The types of both species were taken on the south side of the island on the 

 shore of Kwantung Straits. Other specimens were secured at a point about 

 2 rnUes farther north. The names which I have used for the two species 

 were suggested by Dr. Abbott's note that the smaller animal squeals piteously 

 when caught, while the larger is silent. 



Mus PULLivENTER, new species. 



Type.— Adult male (skin and skull). No. 111790, U. S. N. M. Collected on 

 Great Nicobar Island, Nicobars, March 12, 1901, by Dr. W. L. Abbott. 

 Original number, 927. 



