Dry, powdered unfixed preparations of shells and otoliths were examined Calcium carbonate occurs in 2 crystal forms, calcite or aragonite in the egg shell. Otoliths also form 1 or the other type crystal. In birds, calcite is the form found in both structures (White Leghorn hen). In the turtle, Emys blandingi, the egg shell is aragonite. Previously no turtle otoliths were reported but in E. blandingi they were made of aragonite.