168 



I presume this formation has been generally considered to overlie 

 immediately the Oamaru building stone. 



At one point near the south side of the Oamaru Cape Cliffs, just below 

 where the hill slopes away southwardly, may be seen the " Blue clay " with its 

 underlying rocks. At first sight it seems to be a horizontal bed, capped by a 

 seam of yellow clay ; but a closer inspection shows that there are hard seams, 

 several inches thick, running through it, dipping to the south ; and that these 

 show the original planes of stratiii cation, is evident, because the imbedded 

 fragments of flat shells, and thin seams of shells, lie in parallel planes. Also, 

 the same rocks form, at this place, outlying reefs, dipping in the same direction, 

 having the soft parts eaten away by the action of the waves, so that the upper 

 part of the clay and adjoining rocks (on which lies a single layer of hard 

 water-worn limestone, say six inches to a foot in thickness), must have been 

 worn to a level, and the upper portion of the clay altered in colour, after 

 being tilted by the force of the volcanic outbursts which formed the Cape 

 hills. 



Interposed between the " Blue clay " and Oamaru stone, is a layer of sand 

 like that in Hutchinson's lime kiln, containing numbers of Terebratulse, 

 Pecten, Hntchinsonia, etc., and irregular masses of dislocated rock, altered, I 

 suppose, by heat. 



On looking over the foregoing I think you may add to the previous list of 

 fossils, one new species of Limopsis, and one new Struthiolaria. (List 

 amended.) The Struthiolaria (of a genus you may remember peculiar to our 

 shell province) is interesting, as showing a marked approach to the genus 

 Aporrhais. Comparing it with S. straminea, the body is more slender, the 

 mouth more expanded, and the outer lip, instead of having two slight rounded 

 projections, has one clawdike expansion. A fine Turritella, of which you have 

 at least one specimen from the Waitaki, attaining a circumference of about 

 four and a half inches, is not uncommon, and I have one Scalaria (which 

 seems common to this and the Oamaru stone) about four inches in circum- 

 ference. It is singular that the only shell retaining any colour is a large 

 Lima, of which genus I believe all the recent species are destitute of colour. 

 Possibly, however, the colour has been induced by chemical action, during its 

 long sojourn in the clay ; and this shell was, perhaps, in its day and genera- 

 tion, of as pure a white as its descendants of our times. I have one valve of 

 this Lima, measuring five inches in length. The list I sent you contained 

 seventy-five genera, with the two now mentioned, seventy-seven, of which I 

 believe fifty -one to be extinct, and twenty-six perhaps alive ; but I have more 

 confidence in the dissimilarity of the fifty-one, than in the similarity of the 

 twenty-six ; and I have a number of imperfect shells and fragments, evidently 

 different from any we have found recent, but of which I have not yet been 

 able to determine even the family ; so I think it not unreasonable to suppose, 

 that the proportion of extinct is understated above- 

 Without presuming, of course, to speak positively, I cannot help a strong 

 impression that these results indicate a much higher antiquity to this 

 formation than has been hitherto assigned to it. As far as I have seen it 

 noticed, it is put down as Pliocene, or Pleistocene* — a time I suppose when 

 nearly the present disposition of land and water obtained ; while if it has to 

 be referred back to the Miocene, or possibly the Eocene, we must imagine a 

 period when these islands bore only a rude general resemblance to our New 

 Zealand of to-day. (?) Even on this spot, I think it can be shown, that when these 



* A series of fossils from this formation, now in the Dunedin Museirn, was exhibited 

 in the G-eological Survey Collection, in the N. Z. Exhibition, 1865, as Eocene. See 

 "Catalogue of N.Z. Exhibition,'' p. 58 ; and "Juror's Reports," p. 263. — Ed. 



