338 H. I. JENSEN. 



feet deep, quite deep enough to obscure a horse aud its 

 rider from the view of an observer on a hummock 10 yards 

 away. The hollows vary in length from 25 to 50 or even 

 100 feet. The country is far too rough to ride over even 

 when cleared. 



Gilgai country may occur in small areas of only a few 

 acres, but where typically developed a gilgai area has fre- 

 quently an extent of several square miles, and along the 

 northern edge of the Pilliga Scrub these gilgai areas occur 

 close together, separated from one another by narrow belts 

 of red soil, and of light sands lining the creek courses, over 

 an area about 25 miles long and 5 to 10 miles wide. This 

 portion of the Pilliga Scrub we can call the 'Gilgai Belt.' 

 It has an area of about 200,000 acres, adjacent to the towns 

 of Narrabri and Wee Waa. 



The gilgai lands are, I believe, on the average more low- 

 lying than the belts of red soil and the diluvial sands of the 

 aggraded creek banks. I am informed that a heavy flood 

 inundates all the gilgai country before the red soil belts 

 and sandy belts are flooded. 



II. Distribution of Gilgai Country. 

 As far as I am aware no description of * gilgai ' country 

 has ever been published, but it has often been observed by 

 surveyors and scientists in different parts of the State. 



Mr. R. H. Oambage, L.s., f.l.s., informs me that he has 

 traversed gilgai country in many districts, and that, accord- 

 ing to his experience, it is found in various places along 

 the western slopes, north, central and south. It occurs 

 usually near the white box belt, the zone of Eucalyptus 

 albens. 



Mr. E. O. Andrews, b.a., has had a similar experience of 

 the distribution of typical gilgai country. He has informed 

 me that he has only met with this type of surface on the 



