sporocyst

 An asexual zooid, usually forming one of a series of larval forms in the agamic reproduction of various trematodes and other parasitic worms. The sporocyst generally develops from an egg, but in its turn produces other larvæ by internal budding, or by the subdivision of a part or all of its contents into a number of minute germs. See Redia.  [1913 Webster]

 Any protozoan when it becomes encysted and produces germs by sporulation.  [1913 Webster]