TULLY LIMESTONE. 
215 
The mass is too thin to be of importance in its effects upon springs or upon the character 
of the soil. It is the most southern limestone in the State from which lime is burned, and in 
this respect is important to the inhabitants of the district along which it extends. Being from 
six to eight or ten miles south of any other point where limestone is quarried, it becomes of 
great value, both for burning to lime and as a rough building stone. 
Organic Remains of the Tully Limestone. 
As a general fact, organic remains are rare in this rock within the district. In the Third 
District, however, they are more common, but they are of the same forms in both. Besides 
those figured below, there is a species of Cyathophyllum, which is abundant at Bellona in 
some thin shaly layers in the upper part of the rock. In many localities fragments of fossils 
are found, though perfect ones are not met with. This seems more extremely so towards its 
western termination. 
92. 
1. Atrypa cuboides? 2. Orthis resupinata. 3. Atrypa lentiformis. 4. Atrypa affinis. 
1. Atrypa cuboides? (Reference, Sowerby, Geol. Trans. 2d series, Vol. 5, pi. 56, f. 24. 
Phillips, Palaeozoic Fossils, page 84, pi. 34, f. 150.) — Sub-globose or cuboidal; front mar¬ 
gin of the lower valve extremely elevated, occupying a deep sinus, with nearly parallel sides 
in the upper valve; lower valve, with the exception of this process, nearly flat; beak small. 
This fossil is readily known by the square sinus of the upper valve, the strongly ribbed 
process which fills it, and the sharp edges of the shell at the junction of the valves. It seems 
scarcely possible that this shell can be different from the English specimens, though both 
Sowerby and Phillips describe the A. cuboides as having fifteen ribs on the mesial sinus, 
while ours has but from six to eight. In other respects there is a precise correspondence. 
The ribs on the process of the lower valve, and on the elevated portion of the upper valve, 
are much stronger than elsewhere on the shell. 
Locality —Bellona, Ontario county. 
