Original Description of Aporrhais potomacensis by Clark & Martin, 1901:
- "Shell fusiform; spire elevated, pointed; body whorl large; outer lip much expanded; digitations, two, slender and long; posterior digitation about twice as long as the anterior; callus on the inner lip thick; whorls strongly convex and somewhat angulated below the middle; body whorl with two obtuse revolving ribs, which extend down the middle of the digitations, and disappear in the opposite direction beneath the callus on the labium; about twenty longitudinal ribs on each whorl, with a deep curve below the suture, overridden by fine, raised, close-set, revolving lines."
Locus typicus: 1 mile northeast of Piscataway, Paspotansa Creek, 2 miles below Potomac Creek, Maryland, USA.
Stratum typicum: Aquia Formation, Paleocene
- Clark, W.B. & Martin, G.C., 1901. The Eocene deposits of Maryland: Maryland Geological Survey, Eocene, p. 1-91, 122-204, 258-259.
- T. G. Gibson and L. M. Bybell (1991) - Paleocene-Eocene Boundary Sedimentation in the Potomac River Valley, Virginia and Maryland. I.G.C.P. Project 308.