a, b, c - Holotype of U. viterboana alva, d - unknown specimen (BMNH) glued to card with holotype (see text) (Genit. Prep. SRS-453). Image from: Steinhauser, Stephen Rogers 1981. A revision of the proteus group of the genus Urbanus Hübner. Lepidoptera: Hesperiidae. Bulletin of the Allyn Museum 62: 1-41, 61 figs. (4 September). p. 17-19, f. 35