What is "didelphys virginiana"

Opossum \O*pos"sum\, n. [Of N. American Indian origin.] (Zo["o]l.) Any American marsupial of the genera Didelphys and Chironectes; called also possum. The common species of the United States is Didelphys Virginiana.

Note: Several related species are found in South America. The water opossum of Brazil ( Chironectes variegatus), which has the hind feet, webbed, is provided with a marsupial pouch and with cheek pouches. It is called also yapock.

Opossum mouse. (Zo["o]l.) See Flying mouse, under Flying.

Opossum shrimp (Zo["o]l.), any schizopod crustacean of the genus Mysis and allied genera. See Schizopoda.