534 Transactions. — Geology. 



27. Corbula caniculata, Hutton. 



28. Cliione crassa, Quoy and Gaimard. 



29. Chione vellicata, Hutton. 



30. Dosinia magna., Hutton. 



31. Gucuilcea alta, Sowerby. 



32. Glycimeris globosa, Hutton. 



33. Leda fastidiosa, Hutton. 



34. Flabellum radians. 



35. Balanophyllia hectori, Tenison-Woods. 



There are several species in the Kakahu collection in the 

 Canterbury Museum which were not found by me. They are 

 as follows : — 



36. Scaphella kirki, Hutton. 



37. Struthiolaria spinosa, Hutton. 



38. Ostrea angasi, Sowerby. 



39. Pinna zelandica, Gray. 



Of the thirty-six molluscs in the above list, ten, or 28 per 

 cent., are still living. 



Tkelissic Basin. 



This place was examined by Sir Julius von Haast in 1867, 

 examined and mapped by Sir James Hector in 1872, by Mr. 

 McKay in 1879,* and by Captain Hutton in 1886.1 Last 

 April I spent four days examining the section along the course 

 of the Thomas Eiver, which runs through the centre of the 

 basin. Every one had given a different interpretation of the 

 geology of the basin, and for that reason I devoted my time to 

 one section, in the hope that I should be able to arrive at some 

 definite conclusion as to the sequence and relationship of the 

 different beds. In this I was disappointed. 



The Cretaceous and Tertiary beds are not folded so as to 

 be involved in the tectonic arrangement of the mountains 

 which surround the basin ; but they are faulted, disturbed by 

 volcanic intrusions, and covered over wide areas by heavy 

 deposits of terrace gravels, which make it impossible to get a 

 continuous section in any direction across the basin. It is for 

 these reasons that the sections shown by Sir James Hector { 

 are so unlike those drawn by Captain Hutton. § I agree with 

 Sir James Hector and Mr. McKay in correlating the lower 

 limestone with the Weka Pass Stone. But Mr. McKay goes 

 further than this. He correlates the lower limestone (Weka 

 Pass Stone) with the Ototara Stone (Waitaki Stone), a view 



* Reports of Geol. Expls., 1879-80, p. 54. 



t Hutton, "On the Geology of the Trelissic or Broken River Basin, 

 Selwyn County " (Trans. N.Z. Inst., vol. xix., 188G). 

 \ Reports of Geol. Expls., 1879-80, p. xx. 

 § Trans. N.Z. Inst., vol. xix., 188G, p. 408. 



