Fauna of the Morrow Group 
81 
area but there the seas were in many localities clear and hos- 
pitable to life from the beginning of the period. Two faunas 
from the Cordilleran region bear rather striking resemblances 
to the Morrow fauna. 
One of these was described in 1873 by Meek^i from collections 
made at “Old Baldy” near Virginia City, Montana. Both Ulrich 
and Schuchert have pointed out the similarities which appar- 
ently exist between the Old Baldy fauna with its Pentremites, 
Eumetria, and other forms of a Mississippian aspect associated 
with Squamularia and other Pennsylvanian types, and the Mor- 
row fauna. Further study of the Montana faunas may prove 
that certain of the Carboniferous limestones of that state are 
of early Pottsville age. 
Fully as significant a resemblance exists between the Morrow 
fauna and that of the Lower Aubrey group described by White^^ 
from collections made by the Powell Survey in the vicinity of 
the Uinta Mountains in Utah. The following list with the com- 
parisons appended shows the similarity of the faunas: 
Lower Aubrey Fauna 
Morrow Fauna 
Chaetetes milleporaceous 
ibid. 
Fistulipora sp. 
cf. 
Fistulipora sp. 
Syringopora sp. 
Amplexus zaphrentiformis 
cf. 
Amplexus corrugatus 
Lophophyllum proliferum 
— ■ 
Lophophyllum profundum 
Lithostrotion sp. 
Acervularia sp. 
Archeocidaris cratis 
cf. 
Archeocidaris sp. 
trudifer 
Erisocrinus typus 
cf. 
Delocrinus dubius 
Scaphiocrinus carbonarius 
Eupachycrinus platybasis 
cf. 
Eupachycrinus cf. magister 
Polypora sp. 
cf. 
Polypora magna 
F'enestella sp. 
cf. 
Fenestella 3 sp. 
Archimedes sp. 
cf. 
Archimedes juvenis 
Discina sp. 
cf. 
Orbiculoidea missouriensis 
Productus punctatus 
— ■ 
Pustula punctata 
longispinus? 
cf. 
Pustula sublineata 
costatus? 
cf. 
Productus morrowensis 
costatus var. 
prattenianus 
— 
Productus cora 
semireticulatus 
nebraskensis 
— 
Pustula nebraskensis 
