Philip W. Smith

Natural History of the Racer Coluber constrictor

Natural history of the racer Coluber constrictor , Natural history of the racer Coluber constrictor , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Relationships of the Topminnows Fundulus notatus and Fundulus olivaceus in the Upper Mississippi River Valley

In the upper Mississippi River valley, Fundulus notatus and F. olivaceus differ markedly in pattern and size, slightly in scale and ray counts and in proportions. These species tend to be microgeographically and ecologically separated, with notatus occurring in low-gradient streams and sloughs in relatively level areas, and olivaceus in fast, gravelly streams in upland areas. They have occurred together for 60 years or more in several stream systems in southern Illinois, and comparison of allopatric and sympatric samples suggests some character displacement. The more northern notatus is unable to penetrate the range of olivaceus in highlands but does so along the broad Mississippi River floodplain.

Parasitic T.ampreys of the Genus Ichthyomyzon in the Rivers of Illinois

cerned over the possibility that the sea lamprey, Petromyzon marinus Linnaeus, might have invaded the river systems of the state from Lake Michigan. Because of their concern, the Illinois State Natural History Survey and the Illinois State Department of Conservation began a survey of the parasitic lampreys of the larger rivers in 1949, and continued the investigation through 1959. Of the 454 lampreys taken from the rivers during the study all but one belonged to the freshwater genus Ichthyomyzon. The single sea lamprey (now in the Natural History Survey collection) was reported to us as having been taken from the Du Page River, a tributary of the Illinois River in extreme northeastern Illinois; but inasmuch as substantial evidence that the collector actually found the specimen in the Du Page River has not been obtained, we consider the record as doubtful. The occurrence of the sea

A New Toad from the Highlands of Guatemala and Chiapas

IN a small collection of amphibians and reptiles secured in southern Chiapas by C. J. and M. Goodnight and L. J. Stannard in August, 1950, were four juvenile toads tentatively regarded when received as immature Bufo valliceps Wiegmann. A reexamination of these toads has revealed that they are quite unrelated to valliceps and are of an apparently undescribed species. Four additional specimens of the same toad, 175