410 Transactions. — Geology* 



13. Pleurotoma sulcata, Hutton. 



14. Clathurella haviiltoni, Hutton. 



15. Natica darwinii, Hutton. 



16. Natica gibbosa, Hutton. 



17. Natica ovata, Hutton. 



18. Natica hamiltoni, Tate. 



19. Cerithium nodosum, Hutton. 



20. Struthiolaria sjnnosa, Hutton. 



21. Struthiolaria obesa, Hutton. 



22. Struthiolaria cingulata, Zittel. 



23. Trochita neozelanica, Lesson. 



24. Crepidula incurva, Zittel. 



25. Turritella tricincta, Hutton. 



26. Turbo superbus, Zittel. 



27. Cantharidiis tenebrosus, Adams. 



28. Dentalium conicum, Hutton. 



29. Mactra discors. Gray. 



30. Cytherea enysii, Hutton. 



31. Cytherea assimilis, Hutton. 



32. Chamostraa albida, Lamarck. 

 83. Crassatella ampla, Zittel. 



34. Cardita patagonica, Sowb. 



35. Pectunculus laticostatus, Quoy and Gaim. 



36. Mytilus latus, Chemnitz. 



37. Permt, sp. ind. 



38. Anomia undata, Hutton. 



Li the plant-beds, above the lignite, casts of two small 

 bivalves have been obtained. They have been referred doubt- 

 fully to Unio, but they are much smaller than any species known 

 to me, and one of them appears to have been radiately ribbed ; 

 they have the shape of Callista. 



Origin of the Trelissick Basin. 



Mr. McKay appears to be of opinion that the form of this 

 basin is due, in large part, to foldings of the rocks by compres- 

 sion, subsequent to the deposition of the Pareora System ; aud 

 it is to these foldings that he would attribute the upheaval of 

 the surrouuding mountains."'''' This opinion is, perhaps, to some 

 extent, due to the very exaggerated sections which accompany 

 his report ; but in reality there is no dip in either the Pareora 

 or the Oamaru rocks which cannot be easily accounted for (1) by 

 original deposition ; or (2) as the effect of subsequent landslips or 

 faults ; or else (3) by being in the immediate neighbourhood of 

 a volcano. The only localities where the dip is more than 30° 

 are in Coleridge Creek, near the volcano ; in the upper gorge of 

 the Porter ; and the plant beds at the Thomas where the road 



* " Rep. Geol. Expl.," 1879-80, p. 59, 



