The shell of Theodoxus fluviatilis is somewhat depressed ( with an usually low spire ) , strongly calcified .
The shell of Theodoxus fluviatilis has 3 -- 3.5 whorls ( including the protoconch ) .
The shell of Theodoxus fluviatilis is somewhat depressed ( with an usually low spire ) , strongly calcified , and has 3 -- 3.5 whorls ( including the protoconch ) .