72 
Kirtley F. Mather 
tion of Utah and Idaho, and is present in the late Pottsville 
Mercer limestone of Ohio. In Kansas it ranges throughout the 
entire Pennsylvanian section. The other species is a new one 
with indefinite affinities. 
The Protremata are far more abundant. Rhijndomella is rep- 
resented by two species, one of which, R. yecosi, is the only 
species of this genus heretofore recorded from the Pennsylvanian 
of North America. It occurs throughout the Coal Measures of 
the Mississippi valley as well as in several of the Upper Carbon- 
iferous limestones of the west. Schizophoria resupinoides is 
present in great numbers. This form, probably a descendant 
of the Mississippian *§. resupinata, has been described from the 
Coal Measures of Kentucky, Illinois, and Arkansas, and occurs 
in the Carboniferous limestones of New Mexico. Orthotetes 
ranges throughout the Carboniferous strata of North America. 
One of the two Morrow species referred to it is 0. rohusta, a 
form common in the Coal Measures of Illinois, Iowa, and Mis- 
souri, and occurring in the Ames limestone, of Conemaugh age, 
in Pennsylvania. Meekella striatocostata is commonly present 
throughout the Coal Measures of the central states and has fre- 
quently been identified from the Pennsylvanian limestones of 
the west. The genus is unknown in Mississippian rocks. 
The Productidae are present in the abundance and diversity 
ordinarily found in the later Paleozoic faunas. Chonetes laevis 
which has frequently been confounded with C. geinitzianus is 
apparently a valid species which seems to be confined to the 
earlier Pennsylvanian rocks and is replaced in the middle por- 
tion of the system by the form with a distinct sinus with which 
it has been confused. It occurs in the Cherokee shales at the 
base of the Kansas Pennsylvanian and in the Lower Coal Meas- 
ures of Iowa. Two other species of this genus are here described 
for the first time. 
Productus, as restricted by Thomas,’^'^ includes seven of the 
Morrow forms, only three of which have been previously known. 
The form identified as P. gallatinensis is certainly conspecific 
with the fossils from the Hermosa limestone of Colorado to which 
Girty has applied that name and it is closely related to, if not 
identical with, P. boonensis described by Swallow but never illus- 
trated, from the Coal Measures of Nebraska and Kansas. 
