• Body flattened with thoracic and abdominal segments expanded so that legs and head are obscured from above
• Six tiny legs that contain four segments are concealed underneath the body
• Tarsal claw(s) can be found on the last leg segment
• Head with antennae inserted close together between eyes constricting clypeus from frons
• Gills found on the ventral side of the body

• Video: Dorsal and ventral views of Psehpenidae with focus on moving and gill aeration

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