For the purpose of the Inheritance Tax Law the term “joint tenancy” includes any ownership of property by two or more persons whereby the property is held in the joint names of such persons, or is deposited in a bank or other depositary in their joint names subject to payment to either or any of them during their lives or to the survivor or survivors upon the death of any one. The distinguishing incident of this character of ownership is the right of the surviving owner to the sole and immediate ownership, possession, and enjoyment of the property by virtue of his survivorship.