Teller—An Operculated Gastropod. 
1287 
evidently unknown, and there were several varieties associated 
in the layers where found but little consideration was given to 
the suggestion until at last the finding of a specimen of a gastro¬ 
pod with the operculum in its natural position confirmed the 
supposition, other forms of operculum from other localities in 
the Niagara of Wisconsin are now known hut the species to 
which they belong have yet to be identified. 
In the years 1860-61 the late Prof. James Hall, then the 
geologist of the state of Wisconsin, made large collections of 
fossils from the formations of the south-eastern portion of the 
state, many of the specimens were described in his report of the 
Geology of Wisconsin in 1861, and in the first volume of the 
Geology of Wisconsin in 1862 all without figures. In the twen¬ 
tieth annual report of the state cabinet of natural history of the 
state of New York 1867, and in the revised edition of the 
same report 1868, he gives a redescription of these species with 
figures adding several new species not previously described, 
among them several gastropods, to one of them on plate 15, fig¬ 
ure 19 he has given the name Murchisonia conradi. 
Genus murchisonia, Phillips. Murchisonia conradi , JN. S. 
Shell turreted, somewhat rapidly ascending, consisting of about 
seven volutions which are distinctly carinated on the mid¬ 
dle or scarcely above the middle. Above the carina the 
surface is slightly concave, and below the carina very 
slightly rounded; while the lower side of the last volution 
is regularly rounded and somewhat ventricose. 
The surface has been finely striated with irregular undula¬ 
tions corresponding with the lines of growth where the striae 
have become crowded. The entire length of the shell to the base 
of the last volution is one and nine-tenths inches and the diame¬ 
ter near the base nine-tenths of an inch. 
