North-American Unionida of conservation concern in the Museo di Zoologia dell’Università di Bologna, Italy. A-B. Pleurobema clava (Lamarck, 1819), Critically Endangered (IUCN), Endangered (USFWS), Ohio River, length 50 mm; C-D. Quadrula metanevra (Rafinesque, 1820), Critically Endangered (IUCN), Ohio River, length 59 mm; E-F. Margaritifera margaritifera Linnaeus, 1758, Endangered (IUCN), small streams in Pennsylvania, length 123 mm. Scale bar 1 cm.

 
 
  Part of: Albano P, Bongiovanni B, D'Occhio P, Sabelli B (2014) Natural history museums as repositories of endangered diversity: the case of the United States Unionida in the Museo di Zoologia dell’Università di Bologna. Zoosystematics and Evolution 90(2): 105-111. https://doi.org/10.3897/zse.90.8231