The recent species of the genus Succinea are certainly puzzling, but those which are found as fossils in the loess deposits of the Missouri and Mississippi valleys are positively bewildering. The fossil forms belong principally to the avara and obliqua groups, but few specimens belonging to the ovalis group occurring. Without entering into a detailed discussion of the various forms it may be briefly stated that an examination of the specimens, both recent and fossil, which are herewith submitted, will show the following facts.
Proceedings of the Iowa Academy of Sciences
©1893 Iowa Academy of Science, Inc.
"Variation in the Succinidae of the Loess,"
Proceedings of the Iowa Academy of Science, 1(Pt. 4), 111-111.
Available at: https://scholarworks.uni.edu/pias/vol1/iss4/37