84 Transactions. 
zon.” But each of them taken by itself is a series of fossiliferous beds 
of great thickness. How then, may I ask, can the two when combined 
form one horizon ? 
line of argument, we might as well deny the separation of the Ordovician 
and Silurian, Triassic and Jurassic, Miocene and Pliocene ; or deny the 
right of historians to divide historic time into iods. 
ing my survey of the Oamaru district in 1916-17 I discovered a 
hitherto-unknown fossiliferous horizon in the Upper Hutchinsonian at 
Target Gully, containing many casts of Pachymagas parki, and separated 
from the overlying Target Gully Awamoan shell-bed by about 20 ft. of 
soft glauconitic sandstone. From the friable glauconitic sandstone of this 
horizon (bed c, fig. 35, Geol. Surv. Bull. No. 20, p. 80) I collected seventy- 
two species of Mollusca. Mr. H. Suter, who made the identifications, 
on. 
t think Mr. Uttley's argument is sound ; and if we followed 
it to its logical conclusion we should get curious results. It is well known 
that station exercises a powerful influence on the distribution of molluscan 
life. Of the few molluses recorded from the Oamaru stone none are 
contain only 27 per cent. of living forms. 
The grouping and correlation of horizons based on small collections 
must always be regarded with suspicion. Frequently they give results 
that are altogether erroneous. 
. ln his latest paper Mr. Uttley|| seems to have modified or receded from 
his “ Hutchinsonian-Awamoan " hypothesis. He says: ‘‘(6.) The occur- 
rence of Awamoan fossils in the beds (Otiake beds) above the limestone 
of the Waitaki Valley, and the fact that the Awamoan and Hutchinsonian 
are ‘part and parcel of the same series; as Hutton, McKay, and Park 
have asserted, further strengthens the argument that this limestone [Otiake] 
is Ototaran." 
| ee 
h 26 Н. UrrLEY, (i) Tertiary Geology of the Area between Otiake River (Kurow 
District) and Duntron, North Otago; (2) ‘Tertiary Geology of the Area betten 
iake i Ae У 5 . , 
io i S iver, North Otago, Trans. N.Z. Inst, vol. 52, pp 
t Trans. N.Z. Inst., vol. 52, p. 174, 1920 
t N.Z. Geol. Surv. Pal. Bull. No. 8, p. 54 
8 Loc. cit., p. 58. жшше жа этге 
| Trans. Х.Ж. Inst., vol, 52, p. 182, 1920. 
