HuTTON. — Geology of the TreUsdck Basin. 398 



were rearranged by him, and iu this new arrangement they 

 were included by me in the " Catalogue of the Tertiary Mollusca 

 and Echinodermata of New Zealand" (Wellington, 1873). 



In 1879, Mr. A. McKay examined the district for the 

 Geological Survey, and published, iu 1881, a report which is 

 illustrated by the map and sections made by Dr. Hector in 

 1872.''' In this report, Mr. McKay retains the three formations 

 originally established by Dr. Hector, but makes two important 

 alterations — (1.) He places what was formerly considered as the 

 base of the lower miocene into the upper eocene f ; and (2) he 

 places the fossiliferous tuffs and volcanic rocks of White-water 

 and Coleridge Creeks into the cretaceo-tertiary instead of the 

 upper eocene. Dr. Hector's map appears, also, to have been 

 altered in conformity with this view, for it does not agree with 

 Dr. Hector's statement that the volcanic outburst took place 

 during the upper eocene \ ; and certainly iu 1873 Dr. Hector 

 did not consider the fossils from White-water Creek to belong to 

 the cretaceo-tertiary. 



Last January I spent ten days examining the district, the 

 result being to confirm Dr. Hector's classification of the rocks 

 made in 1872 ; the later alterations of the Geological Survey 

 being mistakes, as I hope to show presently. But I differ from 

 Dr. Hector in his correlation of the lower limestone with the 

 Weka Pass stone, as well as in several details of structural 

 geology. 



In the present paper I have been greatly helped by Mr. -J. D. 

 Enys, F.G.S., who showed me the localities for fossils and for 

 eruptive rocks, and went over the fossils with me and explained 

 my difficulties. The lists of fossils will therefore, I hope, be 

 found tolerably accurate. They are compiled from the collec- 

 tions I have myself examined in the Wellington and Christchurch 

 Museums, and in Mr. Enys' private collection. I have also 

 availed myself as much as possible of the list given by Mr. 

 McKay in his report already alluded to ; but iu this I have had 

 to use great caution, as it contains many errors. § The table of 

 distribution in many cases does not agree with the fossil locality- 

 numbers ; and these locality-numbers often do not refer to the 

 Trelissick Basin at all. Also, some fossils appear to have got 

 into the list by mistake. This, I think, must be the case with 

 Fusiis emjd, (McKay, MSS.,) which is said to have been obtained 

 in localities No. 231 and No. 235. The first of these localities 

 is Ngaruroro Piiver, Napier ; the second is " Plant beds at the 



* "Kep. Geo. Expl.," 1879-80, p. 54. 



t " Eep. Geo. Expl.," 1881, p. 123 ; loc. No. 237 and No. 238. 



\ " Eep. Geo. Expl.," 1879-80 ; prog, rep., p. xxi. 



§ I was much surprised to find this, after having read the excellent 

 lecture on accuracy that Mr. McKay gave us in his report on the Curiosity 

 Shop beds. 



