egg capsule of Haematoloechus medioplexus from the lungs of Rana pipiens, the leopard frog. This is the common digenetic trematode that infects the lungs of frogs.  Egg capsules like this one which contains the miracidium (the cilia can be seen as the small circular bodies inside the capsule), are coughed up and swallowed by the frog, eventually exiting the body through the feces.  A specific snail such as Planorbula armigera, ingests the egg capsules, eventually resulting in the production of cercaria which emerge and enter the cloacal respiratory system of a dragon fly naiad where they encyst as metacercaria.  After completing metamorphosis, the adult dragon fly may be preyed upon by a frog, completing the life cycle.  4000x.