“…Great part of the studies does not inform the criteria used for species identification (Coimbra Júnior and Santos 1986, Vaz et al 1992, Carvalho et al 2001, Medeiros et al 2002, Maldonado et al 2003, Giovanelli et al 2005, Oliveira et al 2007, Agudo-Padrón 2008, Moreno 2008, Núñez 2010, Agudo-Padrón & Lenhard 2011, Pinto & Melo 2012. Considering the recovered studies in which the operational criteria for species delimitation are described, the identification of S. marmorata was based on the anatomy of the soft parts (Souza et al 1998, Thiengo et al 1998, 2001, 2002a, 2002b, Queiroz et al 2002, Teles et al 2002, El-Kouba et al 2009, or the combination of anatomy and shell morphology (Souza et al 2006, Barbosa 2011, León 2011, Mota et al 2012, Souza & Melo 2012, Ohlweiler et al 2013, Cantanhede et al 2014. Nonetheless, only the microanatomy of the penial complex may reveal diagnostic characteristics to distinguish between S. marmorata and A. brasiliensis (Taylor 2003).…”