398 Transactions. — Geology. 



When sufficiently well preserved to show it, this character proved 

 present in every form of PJiynchonella which has been collected from the 

 Secondary and Palaeozoic rocks of New Zealand. 



The recent forms i?. nigricans, and It. psittaoea, also show this character, 

 and it has been detected in an English specimen from the lower greensand, 

 at the base of the cretaceous system. ' 



From the constancy of this character, I think there is sufficient grounds 

 for regarding it as of generic value ; as it has been found in all the species 

 which afford the means of detecting it, and is seen in at least two of the 

 living types of the genus. 



I am not aware that hitherto attention has been called to the presence 

 of this character as distinguishing the genus Rhynchenella. 



From " Woodward's Manual of the Mollusca," p. 376, I take the follow- 

 ing description of the genus : 



" Shell trigonal, acutely beaked, usually plaited ; dorsal valve elevated 

 in front, depressed at the sides, ventral valve flattened, or hollowed along 

 the centre, hinge-plate supporting two slender curved lamellte, dental-plates 

 diverging." and I add teeth crenulated or minutely denticulated. 



Art. LYIII. — On some Indications of Changes in the Level of the Coast 

 Line in the Northern Part of the North Island. 



By S. Peecy Smith. 

 {Read before the Auckland Institute, 15th November, 1880.] 

 Incidental reference to this matter is to be found in various works on New 

 Zealand, more especially in "Hochstetter," the 12 vols, of " Transactions of 

 the New Zealand Institute," and the annual reports of the Geological Sur- 

 vey ; but nowhere, as far as I can learn, has the evidence ever been 

 gathered into one point of view, or dealt with comprehensively. It has been 

 thought therefore, if the information extant is put together, it will be more 

 convenient for reference in the future, and will also perhaps interest the 

 Members of this Institute. With this view I have, in the following notes, 

 collated and summarised from different authorities all that can be found, 

 and propose to supplement it by my own observations, extending over 

 several years, as far as relates to this Northern part of the Island ; though 

 it will be necessary to adduce evidence bearing on the question as affecting 

 the whole of the North Island. I have excluded from consideration the 

 evidence relating to the South Island, although it is more voluminous and 

 clear, the reason of which is in a great measure accounted for by the fact of 



