210 EXTINCT AND VANISHING MAMMALS 



relations are with "Austro-Malayan" rather than with Javan types. 

 He noticed on several occasions the transport of insects to the island 

 by storms "which, during the rainy season, blow occasionally from 

 the northern quarter," but inclines to the supposition that the "rats, 

 the fruit-bat, and possibly some of the land birds, very probably 

 owe their introduction to the island" to the transport by rafts of 

 trees brought by the equatorial drift from the Timor Sea. This 

 island is at least of unusual interest as affording a case in which 

 the native fauna has within a few years been altered as a result of 

 settlement by man, and two of its few native mammals have be- 

 come extirpated. 



G. M. A. 



Broad-toothed Rat 



MASTACOMYS FUSCUS Thomas 



Mastacomys juscus Thomas, Ann. Mag. Nat. Hist., ser. 5, vol. 9, p. 413, 

 1882. ("Tasmania.") 



This rare rat survives in the Otway Forest of Victoria and in 

 Cradle Valley, Tasmania, but little or nothing is known of its present 

 occurrence elsewhere. 



Fur long and soft; general color dark grayish brown above and 

 below, the dorsal hairs tipped with light brown and the ventral 

 hairs with white; tail and feet dark brown. Head and body, 142 

 mm.; tail, 95 mm. (Thomas, 1882, pp. 413-415.) It is a large rat, 

 with a stout build, strong limbs, and a short tail. Head and body 

 (Tasmanian specimens), 170-182 mm.; tail, 110-113 mm. (Finlay- 

 son, 1933a, pp. 126, 128.) Victorian specimens have longer tails 

 (119-124 mm.) (Brazenor, 1934, p. 161). 



The type specimen, from an unspecified locality in Tasmania, was 

 acquired by the British Museum in 1852, and for 80 years no further 

 information seemed to be forthcoming as to its occurrence in that 

 state. In 1931, however, five specimens were collected in Cradle 

 Valley, northwestern Tasmania, at an altitude of about 3,000 feet. 

 The Broad-toothed Rats were living in colonies in grassy areas on 

 open heaths, in association with Eastern Swamp Rats (Rattus 

 lutreolus). "Both rats are probably quite numerous, but the laby- 

 rinths are the chosen hunting grounds of Dasyurus vivverinus [sic], 

 and it was not until several days trapping had got rid of the latter 

 that rats began to be caught." (Finlayson, 1933a, pp. 125-126.) 

 Doubtless this Native Cat acts as a check upon the increase of 

 the rats. 



Lydekker (1885, p. 227) records some bone fragments of Masta- 

 comys juscus from the caves of the Wellington Valley, New South 

 Wales. 



