A Study of the Variation of the Dorsal Scale Rows of Charina bottae (Blainville)

Abstract

IN 1890 Dr. Leonhard Stejneger made a careful study of the genera and species of boids of the western United States and at that time synonymized Wenona Baird and Girard and Psudoeryx Jan with the genus Charina. He recognized Charina bottae (Blainville), C. plumbea (Baird and Girard) and C. brachyops Cope as species, placing Wenona isabella Baird and Girard as a synonym of C. plumbea. In 1900 Cope considered all the rubber-snakes from the Pacific coast as C. bottae, except one specimen from Point Reyes, California, which he believed stands quite outside the wide range of variation of C. bottae, presenting characters which might be and have been considered to be of generic importance. This specimen he retained as C. brachyops. Dr. John Van Denburgh, in 1920, proposed the name Charina bottae utahensis for the rubber-snakes collected in Utah in 1913 by Joseph Slevin. type, from Little Cottonwood Canyon, Wasatch Mountains, Wasatch County, Utah; four specimens from Provo Canyon, two from Fort Douglas and two from Idaho, were said to differ from the Pacific coast form, Charina bottae bottae, by having 41 dorsal scale rows. In 1923 Stejneger and Barbour listed all the above mentioned species, as well as C. b. utahensis Van Denburgh, as synonyms of C. bottae, thus considering all the western American forms as one species. In 1926 Dr. Alexander G. Ruthven presented a concise summary of his findings as to the status of C. b. utakensis, and concluded by saying: The recognition of the Utah specimens as a subspecies should probably be deferred until other distinctive characters are found. Geographic variation in the number of dorsal scale rows in snakes is of rather common