Holotype: "Female holotype from 60 miles southeast of Marathon, Texas, Brewster County (W.W. Milstead), in the American Museum of Natural History" (Muma, 1962, p. 37).

Chelicerae/Operculum Description: "Structure similar to that of H. milsteadi except that this species is somewhat larger, varies in cheliceral dentition (fig. 48), and has specifically different opercula (fig. 49)" (Muma, 1962, p. 37).

Diagnosis: "Although the holotype of the species described here is mangled and incomplete, the proportionate size of the chelicerae and propeltidium, the distinctive cheliceral dentition, and the unusual opercula have made identification and placement possible" (Muma, 1962, p. 37).

Hemerotrecha marathoni  – female holotype AMNH

60 miles SE of Marathon, Texas, Brewster County; coll., W.W. Milstead

(All measurements in sp description except papillae segments)

Measurements: