Betula cordifolia mature to about 3–5 cm long and bear winged nutlets about 2–3 mm long. "Betula cordifolia" is found in Atlantic Canada, Quebec, northwestern Ontario, Northern New York State, and New England. It is generally found in northern habitats or high elevations, particularly on moist ground. "Betula cordifolia" and "Betula papyrifera" are very similar species, indeed they were once considered the same species. The primary methods of distinguishing the one from the other include: Since many of these characteristics vary from tree to tree, ideally several of these characteristics should be noted before making a positive identification. It has been suggested
Mesoraphidiidae genera. Mesoraphidiidae are similar in overall appearance to modern snakefly species, having an elongated prothorax, giving a snake-like profile and from which the common name snakefly is derived. The family was likely tree-dwelling by nature, with larvae being active predators in trunks and branches. Female mesoraphidiids, where known and complete enough, have a long and densely annultated ovipositor which would have been used to lay eggs in crevices of bark. The family was restricted to the Northern Hemisphere, living in the warm temperate and paratropical forest belt that covered portions of Eurasia and North America. As currently described, Mesoraphidiidae contains