Hector.—On the Fossil Reptilia of New Zealand. 355 
bones which have been exposed have a thin squamous structure, with ridges 
radiating from the centres of ossification, that give them the appearance of 
fish bones. The orbit is well defined by a distinct bony arch having a rounded 
margin. 
13. ICHTHYOSAURUS AUSTRALIS, n. sp. 
This genus is only represented in the collection by a single vertebral 
centrum, in a matrix of dark-coloured, fine-grained, micaceous sandstone. 
belongiug to the rocks of Mount Potts, in the Rangitata district of the 
Province of Canterbury. Dr. Haast thus describes the strata from which the 
specimen in question was obtained :—The beds are here “represented by a great 
thickness of dark shales, often becoming so slaty that they may be termed 
clay-slates, alternating with thinner layers of sandstone, sometimes with a 
ferruginous or calcareous matrix. Amongst these occur a few beds of 
conglomerate, which fairly may be termed bone beds, as they consist, besides 
boulders and pebbles of light-coloured slates, of great quantities of well-rounded 
pieces of bones and broken shells, The former often show considerable 
dimensions. I was thus able to measure the proximal end of, probably, a 
humerus, which I found to be 8 inches across, and some other bones of similar 
' dimensions. However, the bones, as before observed, were so much rolled, and 
the cementing medium of such considerable hardness, that I was unable, with 
the tools at my command, to procure any characteristic specimens, but I have 
no doubt that they are of Saurian origin. No teeth were visible amongst this 
bone breccia.”* 
From the associated fossils Dr. Haast concludes that these beds are of 
carboniferous age, but they appear to be identical with strata that, in other 
parts of the colony, are considered to be triassic. 
The foregoing imperfect notes have been prepared under great dis- 
advantages from want of the necessary works of reference, and sufficient leisure 
from other duties for conducting so intricate an investigation ; but it is hoped 
that they will serve to indicate the extraordinary variety and interest of these 
fossil remains, which prove that the ocean during the upper mesozoic period 
was, in the Southern as in the Northern Hemisphere, tenanted by huge Saurians 
performing the functions in the animal economy that are now fulfilled by 
the predaceous Cetacea and marine Carnivora. 
Nore. Jan., 1874.—Having visited the Amuri district since the foregoing 
paper was written, I have arrived at the opinion that the section exposed 
at the Amuri Bluff, from which the Saurian remains were obtained, includes 
a lower formation than any yet found in the Waipara district, and that this 
lower group can be distinguished by its included fossils. 
` The section is much obscured by landslips at the points where the most 
О. с ASO REIN EEA 
* Geol. Surv. Rep., 1873, p. 5. 
