What is the name of cyclopropane with a double bond? I was drawing out all the isomers of $\ce{C5H8}$ and came upon two structures of cyclopropane attached with double bonds. The group is neither a methylene nor an ethyl... what is it? What are the names of these two molecules?
Ethylidenecyclopropane

 Vinylcyclopropane (or Ethenylcyclopropane)