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Aug. F. Foerste 
argillaceous rock within which no structure has been discovered. 
The plates usually are not preserved, so that the fossil usually 
consists of a structureless globular mass with polygonal concave 
depressions locating the former position of the plates. The sur- 
face of the plates frequently is marked by radiating grooves extend- 
ing from the central part toward the angles, near which they 
become indistinct. The fossils usually have a depressed globular 
form. This evidently is due to sagging, the fossil being preserved 
in a clayey matrix. The lower side frequently is indented by a 
broad shallow depression, which also may be due to pressure, but 
which for the present is regarded as diagnostic. 
Geological position. At the base of the Bellevue bed, along the 
railroad two miles southeast of Maysville, Kentucky, in a layer of 
clay two feet thick, and in the immediately overlying limestone. 
Specimens identified as Pasceolus darwini occur in the Valley 
school house railroad cut, between a mile and a half and two miles 
south of Lebanon, Ohio. 
Specimens of Pasceolus retaining only the cavities left by the 
plates and resembling Pasceolus darwini occur a mile and a half 
northeast of Modest, Ohio, along a road crossing the direct road 
to Edenton, a short distance beyond Stone Lick creek, immedi- 
ately above the Platystrophia ponderosa horizon near the middle 
of the Arnheim bed. 
Astylospongia tumidus, James, appears to be identical with 
Pasceolus darwini. One of the best preserved specimens among 
the series of types preserved in the James collection in the Walker 
Museuipi at Chicago University shows a rather deep depression 
on the side usually regarded as the base. Several of these speci- 
mens show distinctly the stellate grooves on the surface of the 
polygonal plates. These specimens are labelled as coming from 
a level of 350 feet above low water in the Ohio river. Miller cites 
Pasceolus darwini from the hills back of Cincinnati at an elevation 
of about 400 feet above low water. From this it is evident that 
Pasceolus occurs at Cincinnati either in the Bellevue horiz(m or 
in the immediately underlying or overlying strata. 
Pasceolus darwini agrees with Pasceolus intermedins in size of 
the body and in the size of the polygonal plates. The types of 
Pasceolus intermedins, Billings, are preserved in the Museum of 
the Geological Survey of Canada. Only the depressions left by 
the plates remain. The specimens are globular and vary from 
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