egg capsule of Toxocara canis.  The ovoid,  pitted capsule wall is typical of this species. It infects canines and poses a considerable risk when the egg capsule is ingested by humans.  The migrating larvae often lodge in vital organs such as the brain, spinal cord, and eyes causing a condition known as visceral larva migrans.  This is the worm you may have seen you dog "cough up" or pass in its stool.  Children should be forewarned not to kiss dogs or let them lick their faces. 400x