• Cephalopharyngeal skeleton with a sclerotized ventral arch below base of mouth hooks, its anterior margin usually toothed
• Body segments often extensively covered with short, fine hairs
• Anal division often somewhat tapered, its apex with tubercles surrounding posterior spiracles that are only slightly elevated

Merritt, R W., K W. Cummins, and M B. Berg. An Introduction to the Aquatic Insects of North America. Dubuque, Iowa: Kendall/Hunt Company, 2008