280 
IOWA ACADEMY OP SCIENCE 
Although the study of the Bryozoa has been difficult and un- 
satisfactory it is believed all precise correlation must be done 
by a close discrimination of the different species of the Bryozoa 
and their horizons. There has been great difficulty in identi- 
fying the smaller Productidae. Although several hundred ven- 
tral valves of Marginifera, Productus longispina and P. miiri^ 
catm, have been examined, but few detached dorsal valves have 
been found, and none of theso show the submarginal ridge that 
characterizes the genus Marginifera. A small brachiopod that 
is especially difficult to identify is found in the City Bluffs shale 
and the Tarkio limestone. At first sight it appears to be a 
Strophalosia. However, it is without a cardinal area and has no 
attachment scar on the ventral valve, which definitely removes 
it from the genus Strophalosia. It is probably an undescribed 
species of Productus. The feature most evident in the fauna of 
the Tarkio limestone is the great abundance of the different 
species of Myalina to be found in this limestone. 
At Coin the outstanding feature of the City Bluffs fauna is 
the abundance of Bellerophon, Chonetes, and Spiriferina pres- 
ent. At New Market in this same shale the species most frequent 
are Marginifera, Productus muricatus^ and Orthothetes crassa. 
Bryozoa are far more abundant at Coin than at New Market. 
The most common fossils of the roof and under shales of the 
Nodaway coal are Euompkalus catilloides and a small variety of 
Orthothetes crassa. In the City Bluffs shale are found speci- 
mens of the marine plant, Conostychus ornat us ^ identification by 
Calvin, Moreover a few specimens of G. hroadheadi have been 
positively identified. It is a surprise that these algae should be 
found so high in the Carboniferous when they were originally 
described as found at the very base of the Coal Measures of 
Missouri. The gymnosperm Carpolithes granulosa is found in 
great abundance in the City Bluffs shale, both at Coin and at 
New Market. As this shale is a marine deposit plant remains 
are rarely found in it. The only plant remains so far found are 
Conostychus, Carpolithes, and Neuropteris. 
The calcareous shales and partings in the limestones carry 
an abundance of Bryozoa. Detached stem fragments of crinoids 
are abundant in all the different strata except the sandstones. 
Several indeterminata have been found which are under further 
