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the whorls of which are small; apex eroded; body 
whorl elongated, obtusely rounded above, and at 
’ base; aperture more than half the length of the shell, 
narrow, much contracted above. 
OBSERVATIONS. 
This species is remarkable for the rude, almost 
deformed whorls of the spire. It inhabits the Tom- 
beckbe river, on the soft limestone banks, and is ge- 
nerally coated with a calcareous deposite. 
MELANIA TROCHIFORMIS. 
Prate VIL.— Fig. 11. 
DESCRIPTION. 
Shell short conical, ventricose, turreted; two spiral 
prominent lines on each whorl, the intervening 
spaces concave; summit of the whorls flattened, an- 
gulated; body whorl angular, with the periphery cari- 
nated; base flattened; aperture small; labrum angu- 
lated in the middle. 
OBSERVATIONS. 
A species easily recognised by its strong ribs, or 
by ‘its sulci, and its trochiform shape. Inhabits 
streams in North Alabama. 
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