Reticulum shading patternsExamples include (a) dark state, Rana kauffeldi (YPM 14143); (b) light state, R. sphenocephala (YPM 14097); (c) R. kauffeldi yellow variant (YPM 13767); (d) R. kauffeldi green variant (YPM 14025). Photographs taken by E. Kiviat (a), M. Cram (b), and BRC (c, d). doi:10.1371/journal.pone.0108213.g004From Feinberg JA, Newman CE, Watkins-Colwell GJ, Schlesinger MD, Zarate B, et al. (2014) Cryptic Diversity in Metropolis: Confirmation of a New Leopard Frog Species (Anura: Ranidae) from New York City and Surrounding Atlantic Coast Regions. PLoS ONE 9(10): e108213. doi:10.1371/journal.pone.0108213 Available online at: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0108213#pone-0108213-g004