Skulls of 30 dogs (Canis familiaris), 29 coyotes (Canis latrans), 18 gray wolves (Canis lupus), 27 red wolves (Canis rufus), and 20 canids of doubtful taxonomic position were measured in 14 dimensions. Multivariate analysis showed complete separation of coyote, dog, gray wolf, and red wolf. Several unknowns fell within the parameters; others fell between and indicate hybridization. Apparent infusion of red wolf genes into the coyote population was occurring in the 1940's and 1950's as the red wolf was being exterminated in Missouri. Five of seven animals with red wolf genes were either black or associated with black animals.