1A-D) from the ventral margin to the pallial line, allowed us to obtain a detailed description from the border toward the inner regions of the shell.
cygnea was carried out to determine the normal pattern of the microstructure and crystal habit from the ventral margin of the shell to the interior shell surface near the pallial line.
A similar phenomenon was also revealed in the inner pallial line regions of the exposed A.
In general, the influence of hydrostatic pressure on the calcification mechanisms, on the regions outside and inside the pallial line, resulted in significant alterations of A.
Observations from the shell border to the pallial line showed unconnected nacreous crystals, indicating a greater number of unfinished nacre lamellae that would be expected for normal bivalve nacre.