Acmostomum rovignense Steinböck, 1933 accepted as Plagiostomum rovignense An Der Lan, 1936 (original description)
Allostoma monophthalmum Steinböck, 1933 (original description)
Aphanostoma chromocephalum Steinböck, 1933 (original description)
Koinocystis dolichocephalus (Pereyaslawzewa, 1892) Steinböck, 1933 accepted as Polycystis dolichocephala (Pereyaslawzewa, 1892) Karling, 1956 accepted as Paulodora dolichocephala (Pereyaslawzewa, 1892) Artois & Schockaert, 1998 (new combination reference)
Koinocystis taeniophoris Steinböck, 1933 (original description)
Microstomum melanophthalmum Steinböck, 1933 (original description)
Polycystis crocea (Fabricius, 1826) Graff, 1905 accepted as Graffiellus croceus (Fabricius, 1826) Hornung, 2016 (additional source)
Polycystis minuta (Uljanin, 1870) Graff, 1905 accepted as Rogneda minuta Uljanin, 1870 (additional source)
Polycystis steueri Steinböck, 1933 accepted as Rogneda steueri (Steinböck, 1933) Karling, 1953 (original description)
Polycystis taeniophoris Steinböck, 1933 accepted as Koinocystis taeniophoris Steinböck, 1933 (original description)
Proxenetes sellai Steinböck, 1933 accepted as Ceratopera sellai (Steinböck, 1933) Den Hartog, 1964 (original description)

Adriatic Sea for Convoluta convoluta (Abildgaard, 1806) 
Adriatic Sea for Convoluta sordida Graff, 1882 
Adriatic Sea for Otocelis rubropunctata (Schmidt, 1852) 
Croatia for Aphanostoma diversicolor Ørsted, 1845 
Croatia for Aphanostoma diversicolor Ørsted, 1845 
Croatia for Aphanostoma diversicolor Ørsted, 1845 
Croatia for Aphanostoma diversicolor Ørsted, 1845 
Croatia for Convoluta saliens (Graff, 1882) 
Croatia for Convoluta schultzii Schmidt, 1852 
Croatia for Convoluta schultzii Schmidt, 1852 
Croatia for Convoluta schultzii Schmidt, 1852 
Croatia for Convoluta schultzii Schmidt, 1852 
Croatia for Convoluta schultzii Schmidt, 1852 
Croatia for Convoluta schultzii Schmidt, 1852 
Croatia for Phaenocora unipunctata (Ørsted, 1843) Bendl, 1908 
Croatia for Phaenocora unipunctata (Ørsted, 1843) Bendl, 1908 
Croatia for Plagiostomum ponticum Pereyaslawzewa, 1892 
Croatia for Stenostomum agile Silliman, 1885 
Croatia for Stenostomum leucops (Duges, 1828) Schmidt, 1848 
Croatian Exclusive Economic Zone for Acmostomum rovignense Steinböck, 1933 
Croatian Exclusive Economic Zone for Allostoma capitatum Uljanin, 1870 
Croatian Exclusive Economic Zone for Aphanostoma chromocephalum Steinböck, 1933 
Croatian Exclusive Economic Zone for Aphanostoma chromocephalum Steinböck, 1933 
Croatian Exclusive Economic Zone for Aphanostoma rhomboides Jensen, 1878 
Croatian Exclusive Economic Zone for Convoluta convoluta (Abildgaard, 1806) 
Croatian Exclusive Economic Zone for Convoluta convoluta (Abildgaard, 1806) 
Croatian Exclusive Economic Zone for Convoluta convoluta (Abildgaard, 1806) 
Croatian Exclusive Economic Zone for Convoluta convoluta (Abildgaard, 1806) 
Croatian Exclusive Economic Zone for Convoluta hipparchia Pereyaslawzewa, 1892 
Croatian Exclusive Economic Zone for Convoluta hipparchia Pereyaslawzewa, 1892 
Croatian Exclusive Economic Zone for Convoluta hipparchia Pereyaslawzewa, 1892 
Croatian Exclusive Economic Zone for Convoluta lacazii Graff, 1891 
Croatian Exclusive Economic Zone for Convoluta pelagica Lohner & Micoletzky, 1911 
Croatian Exclusive Economic Zone for Convoluta sordida Graff, 1882 
Croatian Exclusive Economic Zone for Convoluta sordida Graff, 1882 
Croatian Exclusive Economic Zone for Convoluta sordida Graff, 1882 
Croatian Exclusive Economic Zone for Koinocystis taeniophoris Steinböck, 1933 
Croatian Exclusive Economic Zone for Microstomum melanophthalmum Steinböck, 1933 
Croatian Exclusive Economic Zone for Microstomum ornatum Uljanin, 1870 
Croatian Exclusive Economic Zone for Monocelis lineata (Müller, 1773) Oersted, 1843 
Croatian Exclusive Economic Zone for Otocelis rubropunctata (Schmidt, 1852) 
Croatian Exclusive Economic Zone for Otocelis rubropunctata (Schmidt, 1852) 
Croatian Exclusive Economic Zone for Plagiostomum benedeni (Schmidt, 1852) 
Croatian Exclusive Economic Zone for Plagiostomum chromogastrum Graff, 1890 
Croatian Exclusive Economic Zone for Plagiostomum girardi (Schmidt, 1857) 
Croatian Exclusive Economic Zone for Plagiostomum girardi (Schmidt, 1857) 
Croatian Exclusive Economic Zone for Plagiostomum maculatum Graff, 1882 
Croatian Exclusive Economic Zone for Plagiostomum maculatum Graff, 1882 
Croatian Exclusive Economic Zone for Plagiostomum maculatum Graff, 1882 
Croatian Exclusive Economic Zone for Plagiostomum meledanum Graff, 1911 
Croatian Exclusive Economic Zone for Plagiostomum reticulatum (Schmidt, 1852) 
Croatian Exclusive Economic Zone for Plagiostomum siphonophorum (Schmidt, 1852) 
Croatian Exclusive Economic Zone for Plagiostomum vittatum (Frey & Leuckart, 1847) Jenssen, 1878 
Croatian Exclusive Economic Zone for Polycystis crocea (Fabricius, 1826) Graff, 1905 
Croatian Exclusive Economic Zone for Polycystis dolichocephala (Pereyaslawzewa, 1892) Karling, 1956 
Croatian Exclusive Economic Zone for Polycystis steueri Steinböck, 1933 
Croatian Exclusive Economic Zone for Promesostoma ellipticum (Uljanin, 1870) Graff, 1882 
Croatian Exclusive Economic Zone for Promesostoma marmoratum (Schultze, 1851) Graff, 1882 
Croatian Exclusive Economic Zone for Promesostoma marmoratum (Schultze, 1851) Graff, 1882 
Croatian Exclusive Economic Zone for Promesostoma marmoratum (Schultze, 1851) Graff, 1882 
Croatian Exclusive Economic Zone for Promesostoma marmoratum (Schultze, 1851) Graff, 1882 
Croatian Exclusive Economic Zone for Promesostoma marmoratum (Schultze, 1851) Graff, 1882 
Croatian Exclusive Economic Zone for Promesostoma marmoratum (Schultze, 1851) Graff, 1882 
Croatian Exclusive Economic Zone for Promesostoma solea (Schmidt, 1857) Graff, 1882 
Croatian Exclusive Economic Zone for Promesostoma solea (Schmidt, 1857) Graff, 1882 
Croatian Exclusive Economic Zone for Promesostoma solea (Schmidt, 1857) Graff, 1882 
Croatian Exclusive Economic Zone for Proporus venenosus (Schmidt, 1852) 
Croatian Exclusive Economic Zone for Proporus venenosus (Schmidt, 1852) 
Croatian Exclusive Economic Zone for Proxenetes flabellifer Jensen, 1878 
Croatian Exclusive Economic Zone for Proxenetes flabellifer Jensen, 1878 
Croatian Exclusive Economic Zone for Proxenetes gracilis Graff, 1882 
Croatian Exclusive Economic Zone for Proxenetes sellai Steinböck, 1933 
Croatian Exclusive Economic Zone for Pseudostomum dubium Graff, 1911 
Croatian Exclusive Economic Zone for Pseudostomum inerme (Hallez, 1879) 
Croatian Exclusive Economic Zone for Rogneda minuta Uljanin, 1870 
Croatian Exclusive Economic Zone for Trigonostomum coronatum (Graff, 1882) Graff, 1905 
Croatian Exclusive Economic Zone for Trigonostomum setigerum Schmidt, 1852 
Croatian Exclusive Economic Zone for Trigonostomum setigerum Schmidt, 1852 
Croatian Exclusive Economic Zone for Vorticeros auriculatum (Müller OF, 1784) 
Croatian Exclusive Economic Zone for Vorticeros luteum Hallez, 1879 
Croatian Exclusive Economic Zone for Vorticeros luteum Hallez, 1879 
Italy for Convoluta convoluta (Abildgaard, 1806) 
Italy for Convoluta hipparchia Pereyaslawzewa, 1892 
Italy for Convoluta schultzii Schmidt, 1852 
Italy for Convoluta schultzii Schmidt, 1852 
Italy for Convoluta schultzii Schmidt, 1852 
Italy for Convoluta sordida Graff, 1882 
Italy for Convoluta sordida Graff, 1882 
Italy for Otocelis rubropunctata (Schmidt, 1852) 
Italy for Plagiostomum siphonophorum (Schmidt, 1852) 
Italy for Plagiostomum siphonophorum (Schmidt, 1852) 
Italy for Polycystis crocea (Fabricius, 1826) Graff, 1905 
Italy for Proporus venenosus (Schmidt, 1852) 
Italy for Proxenetes flabellifer Jensen, 1878 
Italy for Pseudoceros maximus Lang, 1884 

 Taxonomic remark

 for Koinocystis dolichocephalus (Pereyaslawzewa, 1892) Steinböck, 1933

Steinböck suggests that the species maybe belongs to Koinocystis, but he expresses a lot of doubt about it. [details]

 Taxonomic remark

 for Koinocystis taeniophoris Steinböck, 1933

Already Steinböck (1933) himself has serious doubts about the placement of this species within Koinocystis.  [details]

 Taxonomic remark

 for Polycystis taeniophoris Steinböck, 1933

Already Steinböck himself states that the available material does not allow allocation to a particular genus. [details]