438 Prof. J. Park — Younger Formations of New Zealand. 



therefore be classed as a Memiraniporella. A photographic figure of 

 a suitably specimen is given to supplement the original diagrams. 



Membeaniporella Jukes-Bboavnei, mihi sp. (PL XIV, Fig. 11.) 



Syn. Crihrilina Jiikes- Browne i, mihi.^ 



Here, too, the structure of the front wall appears to involve the 

 transference of the species to Memhraniporella, and the original 

 diagrams are supplemented by a photographic figure. Restudy of 

 this species has left me with a strong impression that it is closely 

 related to, if not directly descended from, Memhraniporella fallax, 

 mihi, notwithstanding the considerable difference there is between 

 them at first sight. 



EXPLANATION OF PLATE XIV. 



(All figures X 12 diams.) 



Figs. 1, 2. Crihrilina Gregoryi. Different parts of type-specimen. Zone 



(restricted) of A. q^iadrahts. Upham, Hants. 

 Fig. 3. C. Gregoryi. Zone of M. cor-angimizim. Basingstoke. 



Figs. 4, 5. C. suffulta, sp. nov. Zone of M. cor-anguinum. Gravesend. 

 Figs. 6-8. C. Cacus, sp. nov. Trimingham. 

 Fig. 9. C. Dibleyi. 

 ,, 10. Memhraniporella Sherborni. Trimingham. 



,, 11. M. Jukes- Brownei. ,, 



IV. — Classification of Younger Stratified Formations of jS'ew 



Zealand. 



By Professor James Park, F.G.S., Otago University, Dunedin, New Zealand. 



I DO not think there is likely to be much gain from a prolonged 

 discussion of this matter, and for the present I shall content 

 myself with a brief recapitulation of the position so far as it affects 

 the views of Dr. P. Marshall on the one hand and of Captain Hutton 

 and myself on the other. 



1. At various places in the maritime regions of l^ew Zealand, 

 throughout a length of 1,000 miles, there exist a Cretaceous succession 

 andaLower Tertiary succession of sedimentary strata. Both successions 

 contain several fossiliferous horizons, and in many places fossils are 

 numerous and well preserved. By the aid of these fossiliferous 

 horizons the Geological Survey has been able to divide these strata 

 into eight easily recognizable series. 



The Cretaceous strata always rest on Jurassic or older rocks. The 

 Lower Tertiary beds rest sometimes on the Cretaceous strata, but 

 most often on formations older tlian Cretaceous. 



In the central regions of New Zealand, as at Waipara, "Weka Pass, 

 Clarence Valley, Akiteo, and Poverty Bay, the jihysical unconformity 

 between the Cretaceous and Lower Tertiary is absurdly slight, so 

 slight that it cannot be distinguished in many single sections. At 

 each end of this central region, as at Shag Point and Kaitangata in 

 Otago, and Wade and Kaipara in North Auckland, the conformity is 

 quite clear and unmistakable. 



Captain Hntton's first acquaintance with the Lower Tertiary and 

 Cretaceous strata was made in the East Cape and North Canterbury 



' Geol. Mag., 1906, pp. 289-300. 



