1955. The natural history of North American amphibians and reptiles. Van Nostrand Co., Inc., Princeton, New Jersey, ix + 359 pp., 74 figs., 15 tables, 12 pls.

OLIVER, J. A., and SHAW, C. E.

1953. The amphibians and reptiles of the Hawaiian Islands.

Zoologica, 38(5):65-95, 19 figs.

OLSON, R. E.

1959. Notes on some Texas herptiles. Herpetologica, 15(Pt. 1):48, February 25.

ORTENBURGER, A. I.

1927. A report on the amphibians and reptiles of Oklahoma. Proc.

Oklahoma Acad. Sci., 1926, 6(Pt. 1):89-100.

ORTENBURGER, A. I., and FREEMAN, B.

1930. Notes on some reptiles and amphibians from western Oklahoma.

Publ. Univ. Oklahoma Biol. Surv., 2(4):175-88, 2 maps.

OVER, W. H.

1943. Amphibians and reptiles of South Dakota. Nat. Hist. Stud., Univ. So. Dakota, 6:1-31, 20 figs., July.

PARKER, M. V.

1937. Some amphibians and reptiles from Reelfoot Lake. Jour.

Tennessee Acad. Sci., 12(1):60-86, 18 figs., January.

1939. The amphibians and reptiles of Reelfoot Lake and vicinity, with a key for the separation of species and subspecies.

Jour. Tennessee Acad. Sci., 14(1):72-101, 14 figs., January.

1948. A contribution to the herpetology of western Tennessee. Jour.

Tennessee Acad. Sci., 23(1):20-30, January.

PARSONS, T. S.

1958. The choa.n.a.l papillae of the Cheloniidae. Breviora, 85:1-5, 2 pls., January 31.

1960. The structure of the choanae of the Emydinae (Testudines, Testudinidae). Bull. Mus. Comp. Zool., 123(4):113-127, 4 figs., September.

PENN, G. H.

1950. Utilization of crawfishes by cold-blooded vertebrates in the eastern United States. Amer. Midl. Nat., 44(3):643-58, 3 figs., 4 tables, November.

PENNANT, T.

1772. An account of two new tortoises: in a letter to Matthew Maty, M. D. Sci. R. S. Philos. Trans. London, 1771, 61:266-73, 1 pl.

PETERS, J. A.

1942. Reptiles and amphibians of c.u.mberland County, Illinois.

Copeia, 1942(3):182-83, October 8.

PICKENS, A. L.

1927. Reptiles of upper South Carolina. Copeia, 1927(165):110-13, December 23.

PIMENTEL, R. A.

1959. On the a.n.a.lysis of biological data. Turtox News, 37(4):98-101, 1 fig., April.

POPE, C. H.

1935. The reptiles of China. Natural history of central Asia. Vol.

X. Amer. Mus. Nat. Hist., lii + 604 pp., 78 figs., 64 tables, 27 pls.

1949. Turtles of the United States and Canada. A. A. Knopf, New York, 3rd printing, xviii + 343 + v pp., 99 figs., September.

POPE, T. E. B.