216 
GEOLOGY OF THE FOURTH DISTRICT. 
2. Orthis resupinata (Phillips, Palceozoic Fossils, p. 67, pi. 27, f. 115. Spirifera resu- 
pinata of same author, Geol. of Yorkshire. Terebratula resupinata, Sow. Min. Conch, tab. 
325. Anomites resupinatus , Martin. Orthis Tulliensis, Report of Third District, page 
163.) — Transversely elliptical; lower valve very convex, slightly flattened in the centre; 
upper valve convex near the beak, and depressed in front; surface finely radiated. 
When the shell is partially or entirely removed, the surface appears covered with minute 
punctulations. From comparison of specimens, Mr. Conrad says this fossil is identical with 
those sent from England under the name of Anomites resupinatus. It occurs in the mountain 
limestone of England, and in rocks of the same age as the higher shales and sandstones of the 
New-York system. 
3. Atrypa lentiformis (Vanuxem, Geol. Report, page 163). — I am not able to discover 
that this fossil differs from the Atrypa affinis in some of its various appearances. It is usually 
smaller in this rock than that fossil generally is ; but in the next figure is another form, appa 
rently of the same fossil, from this rock. 
4. Atrypa affinis. (For synonymes and authorities, see page 198.) — The valves of the 
shell are much compressed at the margins, giving it the appearance of being surrounded with 
a fringe. The specimens, as commonly obtained, are only that part of the figure which ap¬ 
pears more prominent. 
I am indebted to Dr. H. P. Sartwell, of Penn-Yan, for the specimen from which this figure 
is taken; and also for specimens of the Atrypa cuboides? 
Locality —Bellona, Ontario county. 
93. 
i 
For localities of 
group. 
The figure in the margin is a front view of Atrypa cuboides? the 
others not being quite satisfactory in regard to the form and appearance 
of the ribs on the mesial sinus The elevated portion of the lower 
valve is not quite as great as in Mr. Phillips’s figure. I have not the 
means of referring to Mr. Sowerby’s figure at this time, but that is the 
one by which I had identified this fossil as I then supposed, 
superposition of the Tully limestone, see that head under the Hamilton 
