The genus Pteronarcys was erected by Newman in 1838. In 1843 Newport noted that external gills were to be found on the adult and he expressed the opinion that Pteronarcys must be quite primitive, because external gills do not occur on the adults of other insects. Miller , 1939, studied the embryology of Pteronarcys Proteus and concluded that the generalized development reflected “the natural affinity between the Plecoptera, Isoptera and Orthoptera.” Snodgrass (1935) used Pteronarcys as an example of a morphologically primitive insect. Indeed, Pteronarcys is used in some laboratories as an introduction to the study of insect morphology.