Original caption:
Nallachius americanus (McL.). Drawing of fore and hind wings of a male, collected at Detroit, Michigan, June 28, 1944 (Geo. Steyskal), and now in the Museum of Comparative Zoology.
Note from text:
"I include here drawings of the wings of the male in order to call attention to the anastomosis of the posterior branch of MP with CuA in the fore wing. The amount of anastomosis appears to be constant in the species."
Bibliographic and copyright information:
F. M. Carpenter. Taxonomic Notes on the Dilaridae (Neuroptera). Psyche 54:100-109, 1947.
http://psyche.entclub.org/54/54-100.html
There is no notation of copyright on the material, including in the front matter for that volume (linked from here). Such notice was required for US copyright at that time (see Copyright term and the public domain), so to the best of my knowledge, this illustration is in the public domain.