parts already named. I refer to the thin calcareous mass 
near the base of the shale, which is commonly known as 
the Goniatite Limestone. The interestin this layer is not 
due to any great abundance in the variety of its specimens, 
for the number of varieties is small, even though the 
layer is well described by saying that it virtually abounds 
in its peculiar fossils. But, as its name implies, it is in 
this layer of the Marcellus Shale that the new and ex- 
tremely interesting family of goniatites first makes its ap- 
pearance. In fact the cephalopods as a class are very 
well represented in this layer, for, besides the goniatites, 
we find several species of orthoceras and of nautilus. 
Orthoceras Marcellense. This fossil may be recog- 
nized by its long straight shell, which gradually expands 
from the apex to the aperture. A transverse section is 
circular, and is pierced by a slightly excentric siphuncle, 
situated on the ventral side. 
It is common in nearly all the places where the Goni- 
atite Limestone occurs. Good exposures for obtaining 
specimens are southwest of Manlius, east of Jamesville, 
and east of Marcellus. 
Orthoceras aptum differs from the preceding in that the 
septa are more frequent, the sutures are curved and 
oblique, and the entire appearance of the shell is more 
tapering, due to its more gradualenlargement. Although 
not as abundant as the preceding, it is, nevertheless, often 
found at the above mentioned places. 
Discites Marcellensts is the noted Gonzatites Marcel- 
lensis of the early reports, and is still occasionally called 
by that name. For a long time, however, it has been 
classified as a nautilus, but on account of a closer relation- 
ship to the goniatites than the nautilus usually shows, 
some paleontologists have placed it in the new class, 
Discttes. We consider it a good classification, for the 
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