Catalogue of the primary types of marine molluscan taxa described by Tommaso Allery Di Maria, Marquis of Monterosato, deposited in the Museo Civico di Zoologia, Roma Author Appolloni, Massimo Author Smriglio, Carlo Author Amati, Bruno Author Lugliè, Lorenzo Author Nofroni, Italo Author Tringali, Lionello P. Author Mariottini, Paolo Author Oliverio, Marco text Zootaxa 2018 2018-09-14 4477 1 1 138 journal article 29178 10.11646/zootaxa.4477.1.1 5846b72f-37ca-4033-af93-c20fb297add9 1175-5326 1454652 5A6191BD-03BA-4374-B779-B3E73652BC7C “ OPISTHOBRANCHIA ” The taxon Opisthobranchia P. Fischer, 1883 , has been undergoing a constant critical revision during its history. In recent years there is increasing evidence that it will not survive the molecular revolution in molluscan systematics ( Wägele et al. , 2014 ), so that informal names as “sea slugs” may be provisionally adopted to refer to most “opisthobranch” taxa (e.g. Crocetta et al. , 2015 ). Here, however, listing the material under “ Opisthobranchia ” is also convenient to follow the survey on the Monterosato material already provided by Oliverio & Tringali (2001) .