Morgan. — Geology of the Patea District. 



61 



*Vercondla nodosa (Mart.) 

 Olivella neozelanica (Hutt.) 



*Anciila australis (Sow.) 



*Ancilla depressa (Sow.) 



*Voluta arabica Mart. 



*Terebra tristis Desh. 



*Natica zelandica Q. & G. 

 Polinices ovatus (Hutt.) 



*Cerithidea bicarinata (Gray) 

 Struthiolaria cingulata Zitt. 



*Calyptraea inaculata (Q. & G.) 



*Orepidida costata (Sow.) 



*Crepidula monoxyla (Less.) 



Dentalium solidum Hutt. 

 *Mactra discors Gray 

 *Mactra ovata (Gray) 

 *Mactra scalpellum Reeve 

 *Zenatia acinaces Q. & G. 

 *Gari lineolata (Gray) 

 *Chione mesodesma (Q & G.), or per- 

 haps C. marslialli Cossmann 

 *Dosinia anus (Phil.) 

 *Dosinia subrosea (Gray) 

 *Dicaricella cumingi (Ad. & Aug.) 



Cucullaea attenuata (?) Hutt. 

 *Glycymeris laticostata (Q. & G.) 



Hutton's names have been revised so as to correspond with modern 

 nomenclature, and some changes in the specific names have been made 

 on the authority of Suter. In his paper on the Pliocene Mollusca of New 

 Zealand, published in the Macleay Memorial Volume (1893), Hutton gives 

 a list of Wanganuian Mollusca which broadly is the same as that published 

 by him in 1886, but, besides making changes in nomenclature, he omits 

 eight of the Patea records. It is hardly necessary to go into details. 

 Hutton's lists, whichever may be taken, show a high percentage of Recent 

 species as compared with Marshall and Murdoch's Waipipi list, and differ 

 still more in this respect from the list of fossils collected by the writer west 

 of Patea. If all the fossil records are combined, a total of thirty-four 

 identified species is obtained, of which twenty-five, or 73 per cent., are 

 Recent. 



Since there is reason to believe that the Patea claystones are at lea.-^t 

 as old as the Waipipi beds, as shown by stratigraphical considerations, 

 as well as by the occurrence of a species of Cucullaea (C. attenuata?), 

 Dentalium solidum, Phalium fibratum, and Miltha sp., it seems likely that 

 several of the shells identified by Hutton and Park as belonging to species 

 still living really represented extinct species. Be this as it may, the Patea 

 beds clearly belong to the lower part of the Wanganuian formation — that 

 is, to the stage called " Waitotaran " by Thomson. By restricting the 

 definition of " Waitotaran " it would be possible to introduce a third stage 

 into the Wanganuian, and into this the Patea claystones would no doubt 

 fall. 



Haivera Series. 



As developed near Patea the Hawera series appears to be typically 

 30 ft. to 40 ft. in thickness. The lower layers consist of beach-worn 

 peebles mixed with much sand ; the upper layers are almost wholly sand, 

 which in places is nearly black owing to titaniferous magnetite being 

 present in large quantity. Current-bedding is everywhere very noticeable, 

 and some of the black sand appears to be wind-blown. Along the sea- 

 toast the Hawera beds form the top of the cliff, and therefore cannot be 

 closely examined. On the sides of the Patea Valley their contact with 

 the Waitotaran beds is clearly marked by a sudden change from steep 

 grassy slopes above to claystone cliffs below, and by numerous small springs. 

 At one or two places near Patea, road-cuttings allow the Hawera beds and 

 their contact with the Waitotaran claystones to be closely studied. For 

 example, on the Wanganui road, about a mile from Patea Railway-station, 

 brown weathered claystone (Waitotaran) is overlain by a thin layer of 



