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Transactions. 



dip remain the same throughout as at Kotunui Point there cannot be 

 less than 3,000 ft. of rocks. Our ^collections were made from practically 

 the lowest rocks that are exposed near Tawhiti. The rocks vary a good 

 deal in coarseness and are concretionary in many of the strata, but the 

 fossils did not appear to vary much, and we have made no attempt to 

 distinguish between the faunas of any of the different strata. Actually the 

 thickness of the strata from which we collected was quite small. 



The following is a list of the fossils that were collected by Mr. Bartrum 

 and myself. In identifying the species I have had the invaluable aid of 

 Mr. R. Murdoch. 



Anomia huttoni (Sut.) 



Astraea heliotropium (Mart.) 

 *Atrina sp. 

 *Calliostoma sp. 



Calyptraea sp. 

 *Gonus sp. 

 *Gorbula canaliculata (Hutt.) 



Corbula macilenta (Hutt.) 

 *Cucullaea worthingtoni (Hutt.) 

 *Cylichnella enysi (Hutt.) 

 *Dentaliu'm mantelli (Zittel) 



Dentalium nanum (Hutt.) 

 *Dentalium solidum (Hutt.) 

 *Diploclonta ampla (Hutt.) 

 *Divaricella sp. 



Dosmia greyi (Zittel) 



Dosinia lambata (Gould) 

 *Drillia a£E. novae-zelandiae (Reeve) 

 *Galeodea senex (Hutt.) 

 *Galeodea sulcata (Hutt.) 



Glycymeris laticos.tata (Q. & Q.) (thick 



form) 

 *Macrocallista assimilis (Hutt.) 



Macrocallista multistriata (Sow.) 



Mactra ordinaria (Smith) 



Mactra scalpellum (Reeve) 



Malletia australis (Q. & G-.) 



Extinct species are distinguished by an asterisk. Several of the species 

 that are unnamed are certainly extinct, but are not in a sufficiently good 

 condition of preservation to allow of a satisfactory description being written. 



This list contains fifty-two species, of which twenty-six are extinct — 

 a percentage of 50. If this percentage of extinct species of mollusca is 

 taken as a criterion for the correlation of the strata, the Tawhiti series 

 must be almost exactly midway between the Target Gully series, where 

 there are 35 per cent, of Recent species, and the Waipipi series, in which 

 the percentage is 63. This position of the strata is suggested also by the 

 very nature of the fauna. On the one hand Olivella neozelanica still persists, 

 as well as Diplodonta ampla; while on the other hand a large number of 

 species of Miocene occurrence appear, such as Cucullaea worthingtoni, 

 Siphonalia conoidea, S. costata, Galeodea senex, &c. It is noticeable that 

 there is no species of Limopsis in this collection, and that this genus is 

 absent from those that have been made on the coast-line near Wanganui. 



Myodora subrostrata (E. A. Smith) 



Natica australis (Hutt.) 

 *Natica callosa (Hutt.) 

 *Natica ovata (Hutt.) 



Nucula nitidida (A. Ad.) 



Nuculana jastidiosa (A. Ad.) 

 *Olivella neozelanica (Hutt.) 



Ostrea angasi (Sow.) 



Ostrea corrugata (Hutt.) 

 *Panope worthingtoni (Hutt.) 



Pecten convexus (Q, & G.) 

 *Pecten sectus (Hutt.) 



Pecten zelandiae (Gray) 



Protocardia pulchella (Gray) 

 *Sinum carinatum (Hutt.) 



* Siphonalia conoidea (Zittel) 

 *Siphonalia costata (Hutt.) 



* Siphonalia excelsa (Sut.) 



* Siphonalia nodosa actuicostata (Sut.) 

 *Struthiolaria cincta (Hutt.) 



Tellina eugonia (Sut.) 

 Tellina liliana (Iredale) 

 Turritella symmetrica (Hutt.) 

 Venericardia corbis (Phil.) 

 Venericardia purpurata (Desh.) 

 *Voluta corrugata (Hutt.) 



