164 Robert A. Keble: 



The manner in which a lateral stream of a confined lava fielcJ* 

 passes on to the extensive lava field is described, and the develop- 

 ment of the cross lateral is explained. 



The significance of the cross lateral in the development of the 

 Great Valley of Victoria is commented on. 



The sequence of residuals in the Pre-Older Basalt valleys and. 

 the courses of the streams are indicated. 



A tentative classification of many of the valleys of the two- 

 stream systems is attempted. 



Acknowledgments. 



My thanks are due to Mr. H. Herman, Director of the Geological' 

 Survey of Victoria, who kindly sanctioned the publication of this- 

 paper, for his helpful criticism and facilities placed in my way. 



To Prof. Skeats I am particularly indebted for his exhaustive' 

 and suggestive criticism of the paper in its original form. 



Mr. F. Chapman, of the National Museum, has placed his un- 

 rivalled knowledge of the Victorian Tertiaries at my disposal; for- 

 this and other assistance I desire to acknowledge my great 

 indebtedness to him. 



It wall be recognised that the execution of the plans and sections, 

 accompanying this paper necessitate constructive as well as ordinary 

 draughtmanship. I desire to thank Messrs. C. Glover, T. Dewey 

 and W. E. Bennett, of the Geological Survey Draughting Branch,, 

 for the care they have taken with them. 



Bibliography. 



1. Chapman, F., and Teale, A. 0. On a Limburgite Rock- 



occurring as a Volcanic Plug at Balwyn, near Doncaster. 

 Proc. Roy. Soc. Victoria 24 (N.S.). Part I., 1911, pp. 

 124-134, 2 pi. Sec. 



2. Dutton, Clarence E. Tertiary History of the Grand Canyom 



District. U.S. Geol. Surv., Monograph II. 1882. 



3. Ferguson, W. H. Lower Powlett, Cape Paterson and Inver- 



locli. Memoir No. 8, ^Geol. Surv. Vic. 



4. Gregory, J. W. The Geography of Victoria. Melbourne,- 



1903. 



5. Hall, T. S. Victorian Hill and Dale, Melbourne, 1909. 



6. Harker, Alfred. The Natural History of Igneous Rocks.. 



London, 1909. 



