30 



on one side and concave on the other, the sides respectively facing th(» 

 rising and setting sun." They average about 8 feet in height, the top 

 straight, crowned with irregular little turrets. 



In the " Report of the Horn Scientific Expedition to Central Australia, 

 1896," Professor Spencer says, " At one spot we came across a small patch 

 of the mound nests of what are called the "meridional" or "compass" ants. 

 These are found in other parts of Australia, such as near Cape York and 

 Port Darwin, and the curious feature about them is that the mound, which 

 is 3, 4, or even 5 feet high, is flattened from side to side in such a way 

 that the broad sides face east and west, and the narrow ends north and 

 south ; as it tapers upward it has, seen from the north to south, a wedge 

 shape. There were, altogether, perhaps a hundred of these occupying 

 half an acre of ground, and their shape and bright red colour render them 

 very striking objects. Unfortunately, we met with them in the middle of 

 a long march, when it was impossible to stop and examine them, and my 

 hope that we should afterwards meet with others in similar country was 

 not realized. They are made and occupied by a species of termite, or 

 white ant, and the only other white ant mounds which we saw were a few 

 small grey-coloured ones about 18 inches high on some flats near Lake 

 Amadeus." 



A great deal of interest has been taken by naturalists as to the reason of 

 this termitaria always being built on these angles, and Mr. Jack, in a 

 paper entitled " Notes on the Meridional Ant Hill of the Cape York 

 Peninsula," published in the " Proceedings of the Royal Society of Queens- 

 land, 1897," after describing their structure, advances this theory: " The 

 reason of their being built at this angle is to secure the maximum of 

 desiccation. They do not repair these nests in the long dry season; but 

 when the w^et season sets in repair all damages. Its safety lies in its being 

 dried as quickly as possible. In tropical latitudes it is obvious that this 

 drying can best be secured by placing the longer axis of the structure 

 north and south, so that the rays of the sun may beat upon it during the 

 greater part of the day." A short account of the form of these nests is given 

 in the chapter on Termitidjie in the " Cambridge Natural History," Vol. V, 

 p. 18, with a sketch of a drawing by J. J. Walker, R.N., given to Dr. Sharp. 

 Saville Kent has given some fine reproductions of photographs of these 

 nests in his " Naturalist in Australia." 



This species has a very wide range over Australia, though it is only 

 in some places that it constructs nests; in other places, it lives in small 

 colonies under logs or stones ; and from the latter situations I have had 

 specimens from Kalgoorlie (West Australia), Mackay (Queensland), and 

 many inland places in New South Wales. 



The Red-headed Wliite Ant {Termes ruhriceps, Froggatt). 



The winged form of this handsome termite is unknown ; they live in 



small colonies in the dry parts of Central Australia, and, during the Horn 



Expedition, Professor Spencer obtained several small lots. In one tube 



of specimens was a note that they were taken from a nest at the roots of 



