5 
CHAPTER III. 
A REVIEW OF THE LOCALITIES, WITH A SYNOPSIS OF THE COLLECTIONS 
AND PREVIOUS RECORDS, AND A DISCUSSION AS TO THE GEOLOGICAL 
AGE OF THE BEDS. 
I propose in the present chapter to consider the localities from which the fossil 
plants dealt with here were obtained. These will be enumerated roughly in order 
of their geological age, beginning with the most important of the older Triasso-Rhsetic 
floras, and concluding with the single Neocomian plant-assemblage. In addition to 
details relating to the localities and the collections made from them, with an enu¬ 
meration of previous records, I have also added a list of the species described here. 
Previous opinions in regard to the geological age of the beds are next considered, 
and finally in each case the conclusions which I have arrived at on this point are 
stated. 
Fig. 1. Sketch-map oe the Canterbury District, South Island, showing the Relative 
Positions of the Plant Localities at Mount Potts, and in the Clent and Malvern 
Hills. 
A. The RhvEtic Flora of Mount Potts (Canterbury). 
Locality .-—Mount Potts, situated in Ashburton County, Canterbury, is part of a 
mountain-range lying between the upper Rangitata River on the south-west (fig. 1) 
and the upper Rakaia River on the north-east, and drained by the upper Ashburton 
River on the south-east. Mount Potts itself, a snow-covered mountain 7,197 ft. in 
height, is almost isolated from the range by the Potts River, which flows south and 
west to join the Rangitata River. The fossiliferous localities (figs. 2, 3) lie 
on the western slopes of Mount Potts, principally in Rocky (or Fossil) Gully (the 
faunal locality) and in Tank Gully (the plant locality), the small streams of which 
flow westward to the Clyde River, a branch of the upper Rangitata. 
The beds here consist of a great thickness of dark shales, alternating with thinner 
layers of sandstone. They form a large anticlinal fold in Fossil Gully, where they 
are well exposed for several miles. 
The Collections .—The first fossils found in these beds were Spiriferinas and other 
brachiopoda (see p. 6), discovered by Haast (afterwards Sir Julius von Haast) in 1861. 
