REVISION OF AUSTRALIAN JERBOA MICE. 
Skull.- Bullae medium. About four-fifths of diastema. 
Teeth . — Index of incisors 52°-58°. 
Habitat. — Central, Northern and North Western Australia. 
Type . — In British Museum. 
Fifty-six specimens examined ; Alroy, Tennant’s Creek, Tanami, Reedy 
Creek, Alice Springs, Northern Territory ; Townsend Range, wells on Canning 
Stock Route, Western Australia. Nat. Mus. Nos. R12444, C43-80. 
Three of the original Stalker series (skins) used by Thomas 
in erecting the species were loaned by the West Australian 
Museum. 
The type is an “old female’’ and is large (head and body 
106 mm.) in comparison with the great majority of specimens 
examined including the three Stalker specimens used by Thomas. 
The others are old alcoholic specimens and have probably 
shrunk slightly. The average head and body length of the 
series examined is about 95 mm., though several old females 
range up to 103 mm. Foot, tail, and ear measurements are 
reasonably constant throughout. 
N. fuscus Wood Jones is placed in synonomy. I have not 
seen the type specimens of fuscus, but have examined the 
comprehensive series of animals taken during, or just after, the 
Horne Expedition, which contains a number of the “dark form’’ 
mentioned by Waite and by Wood Jones in his extended 
description of fuscus. 
Oldfield Thomas entirely disregarded the peculiarities of the 
gular area when describing alexis in 1922, though when dealing 
with the same specimens in 1906 and 1921 as mitchelli (in error) 
he noted “a glandular organ on the throat.” 
Formerly fuscus (= alexis) was considered a dark variant of 
cervinus, but the shorter and less woolly fur, the shorter ears, 
and the basally grey abdominal fur of the species now under 
consideration rightly separate it. The colour range of the two 
species over-laps. A series may be so arranged that the colours 
grade uninterruptedly from pinkish-cinnamon (cervinus) to 
Saccardo’s umber (alexis). 
Notomys aquilo Thomas. 
Notomys aquilo Thomas, Ann. Mag. Nat. Hist. (9), VIII, p. 540, 1921. 
Thomas’ description is as follows : “A small pale species with thin fur. 
Size slightly less than mitchelli* Fur thin, poor, not woolly. General colour 
pale sandy brown above, white below, hairs white to their bases. A well- 
marked neck-gland present in the type. Feet thinly haired, flesh-coloured. 
Tail sandy brown, not conspicuously bicolour proximally. Skull delicately 
built. Interorbital region flat, more parallel-sided than usual, less quickly 
♦Later (1922) referred by Thomas to a new species, alexis. 
