摘要：The presence of the blackmask racer (Coluber constrictor latrunculus) in eastern Arkansas was first demonstrated by examination of a series of color slides of live specimens now preserved and deposited in the Arkansas State University Museum of herpetology. Adult color pattern is of paramount importance in the definition of subspecies of C. constrictor, and this is especially true for C. c. latrunculus. This subspecies is characterized by a conspicuous black stripe that extends from the postnasal, through the eye and onto the temporals or anterior dorsal scales. The dorsum is slate gray, and the venter is a pale grayish blue. These identifying color characteristics tend to either fade or be obscured following preservation. Coluber c. latrunculus also has a larger average number of both ventrals and subcaudals when compared to other subspecies of racers in Arkansas. This subspecies was described in 1970 from populations occupying the lower Mississippi River Valley of Louisiana. Recent field guides place the subspecies throughout the alluvial plain and adjacent areas of western Mississippi. With the addition of the blackmask racer, Arkansas now has a total of four racer subspecies, each occupying different habitats within the state.
