Taxonomy and biogeography of Hemphillia (Gastropoda: Pulmonata: Arionidae) in North American rainforests, with description of a new species (Skade’s jumping-slug, Hemphillia skadei sp. nov.)

Species diversity of the genus Hemphillia Bland and W.G. Binney, 1872 (jumping-slugs) was studied across its range in western North America’s inland temperate rainforests. The taxonomic relationships among jumping-slug populations were clarified by integrating morphological, molecular, and biogeographic approaches. A new species, Skade’s jumping-slug (Hemphillia skadei sp. nov.), was discovered in this process and is described herein. We base this taxonomic decision on molecular comparison of representatives from other Hemphillia species and four morphological characters that distinguish H. skadei from its sister species, the pale jumping-slug (Hemphillia camelus Pilsbry and Vanatta, 1897). The distribution of H. skadei and H. camelus is described along with the notable lack of detection of the marbled jumping-slug (Hemphillia danielsi Vanatta, 1914) within the primary survey area.