30 THE NATURALIST IN AUSTRALIA. 



travel underground for from a few feet to many yards at a depth of not more than 

 two or three inches below the surface, its presence and position at such times being 

 revealed by the raising and cracking of the surface of the sand. All efforts to keep 

 the animal alive for a longer period than three or four days have so far failed, the 

 chief difficulty being apparently the food question. The remains of ants were found 

 in the intestines of the first example dissected, and another specimen, while in 

 captivity, is reported to have devoured one of the coleopterous grubs that burrow 

 into and feed upon the roots of the acacia trees, thus demonstrating its normal 

 insectivorous predilections. Not improbably, as is the case with the Echidna, as 

 observed by the author, the favourite food is the tender larval and nymph forms of the 

 ants that would have to be sought for underground, either by burrowing or by the 

 scratching away of the superimposed earth's surface. The experiment of placing 

 adult ants with Notoryctes as a tentative food supply was by no means successful, 

 the animal itself, according to Dr. Stirling, apparently running the greater risk of being 

 eaten. It is much to be feared, under the circumstances so far recorded, that but 

 little chance exists of this interesting little marsupial being established as a permanent 

 tenant of the London Zoological Gardens. 



Of the remaining terrestrial vertebrate fauna of Australia, it will hardly be 

 anticipated that any group would possess the remarkable individuality that is exhibited 

 by the Class mammalia. Numbers of birds systematically migrate, while reptiles, 

 amphibia, and their ova can be transported on floating driftwood. As a conse- 

 quence, we find a very considerable infiltration of Indo-Malay representatives of each 

 of these classes, in the northern, or tropical, Australian districts more especially. 



The highly characteristic Monitors or Varani, the largest of Australian Lacertidte, 

 popularly called " Goohannas," are thus found to be generically identical with forms 

 inhabiting India and North Africa ; while a water-frequenting species, Varanus 

 salvator, growing to a length of six or seven feet, is specifically the same as the 

 Indian and Malay type. There are a number of smaller forms, such as Geckos, 

 Skinks, and other lizards, which possess a similar tropical Indo-Australian distribution. 

 Australia, at the same time, produces several very remarkable Lacertilian types that 

 are found nowhere else outside its limits, as is made evident in a succeeding chapter 

 that is specially devoted to representative members of this animal group. Concerning 

 prehistoric types, it is of interest to record that Australia formerly produced species of 

 Monitors or Varani, and their allies, that are estimated to have been three or four times 

 larger than any existing species. One of these, Megalania prisca, was at least 



