14 PALEOZOIC PALEONTOLOGY 
all of these fossiliferous localities, with the exception of that near 
€arpentersville, are in the upper portion of the formation. The 
Carpentersville locality is probably somewhere in the lower third of 
the entire series. So far as the fossils afford any definite evidence, 
the age of all is upper Cambrian. No middle Cambrian faunas have 
been recognized, although the Olenellus fauna of the Hardyston 
quartzite is usually considered to be of lower Cambrian age, and a 
middle Cambrian fauna would naturally be expected to occur some- 
where in the formation. 
