Hector. ^ — On the Fossil Reptilia of New Zealand. 355 



bones which have been exposed have a thin squamous strncture, with ridges 



radiating fvora the centres of ossification, that give them the appearance of 



fish bones. The orbit is well defined bj a distinct bony arch liaving 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 

 l.telongiug to the rocks of Mount Potts, in the Eangitata 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 procui'e any charactei'istic 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 appea,r 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 ISTorthern Hemisphere, tenanted by huge Saurians 

 performing the functions in the animal economy that are now fulfilled by 

 the predaceous Cetacea and marine Garni vora. 



Note. 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 bj^ its included fossils. 



The section is much obscured by landslips at the points whei'e the most 

 * Geol. Sux'v. Kep., 1873, p. 5. 



