Morphing

  
   
01- A marbled pattern on the ribs
02- The pattern is more present
03- The line appears
04- The pattern under the line vanishes
05- The line becomes quite distinct
06- The pattern disappeared: True lineata
07- The pattern comes back
08- The line becomes fuzzy
09- The line is about to disappear
10- The pattern remains alone
11- return to the initial shell