North American Recent Soft-Shelled Turtles (Family Trionychidae)

by Robert G. Webb

1917. A check list of North American amphibians and reptiles. Harvard Univ. Press, Cambridge, Mass., 1st ed., iv + 125 pp.

1923. A check list of North American amphibians and reptiles. Harvard Univ. Press, Cambridge, Mass., 2d ed., x + 171 pp.

1933. A check list of North American amphibians and reptiles. Harvard Univ. Press, Cambridge, Mass., 3rd ed., xiv + 185 pp.

1939. A check list of North American amphibians and reptiles. Harvard Univ. Press, Cambridge, Mass., 4th ed., xvi + 207 pp.

1943. A check list of North American amphibians and reptiles. Fifth edition. Bull. Mus. Comp. Zool., 93(1):xix + 260 pp.

Sternberg, C. M.

1926. Notes on the Edmonton Formation of Alberta. Canadian Field Nat., 40(5):102-04, May.

Stille, W. T., and Edgren, R. A., Jr.

1948. New records for amphibians and reptiles in the Chicago area, 1939-1947. Bull. Chicago Acad. Sci., 8(7):195-202.