212 Transactions. 



right, and that the average position of the main stream is nearer 

 the left bank. This renders it probable that the rotation of 

 the earth has had a deflecting influence upon the courses of the 

 rivers running through the Canterbury Plains. 



Note 1. — Gilbert says he would not expect to see the influence 

 of the terrestrial rotation marked in rivers that are flowing 

 rapidly and corrading their beds vertically ; but even in this 

 case there must be certain curves in the course of the stream 

 with differential corrasion on the opposite banks. 



Note 2. — -Some of the Canterbury rivers, notably the Ashley, 

 flow almost due east, and in such cases the influences of the 

 rotation must be much less marked. But again, the curves in 

 the course of the river must occur, and even if the general course 

 of the river is due east, in its curves it will flow more or less 

 north or south, and so again present favourable conditions for 

 the effect of the terrestrial rotation to make itself apparent. 



EXPLANATION OF PLATE X. 



In all cases the east side of the river appears on the right-hand side 

 of the section, following the convention in map-drawing. The arrange- 

 ment has the disadvantage, in southwards-flowing rivers, that the left 

 bank is on the right-hand side of the observer. He shoidd imagine himself 

 looking up the stream. 



Each ordinate represents 4 ft., the abscistse 200 yds. The black dot 

 in the bed of the stream represents the position of the main body of water. 



Each ordinate in figs. 7 arid 8 represents 10 ft., the abscissae 200 yds. 



Art. XXI. — Notes on Protective Resemblance in New Zealand 



Moths. 



By Alfred Philpott. 



{Read before the Philosophical Institute of Cdntcrhiiry, Ist November, IdO").] 

 These notes have been put together with a view of forming a 

 base for future work. There is, I am afraid, but little that is 

 aew in them, but I have preferred to risk repetition in order 

 to give them some measure of completeness. 



By far the greater number of our native moths are pro- 

 tectively coloured ; one can easily gauge from this fact the 

 severity of their struggle for existence. Many of our birds live 

 entirely or in part on insect food. The fantails (Rhipidura) and 



