The Headless Hexapod—on the Identity of Planocephalus aselloides Scudder, 1885 (Trichoptera, Hydropsychidae; New Placement) from the Eocene of Florissant

Planocephalus aselloides Scudder, 1885, described in the order Thysanura (in a separate suborder Ballostoma), is based on the head and thorax of the larvae of the caddisfly Hydropsyche scudderi Cockerell, 1909, syn. n. (both from the Eocene of Florissant, United States), interpreted back to front: the head as the abdomen, the proventriculus as buccal plates, etc. The suborder Ballostoma Scudder, 1885, erected in Thysanura, is synonymized with the order Trichoptera Kirby, 1813.