Ciliocincta Kozloff, 1965 (basis of record)
Ciliocincta julini (Caullery & Mesnil, 1899) (basis of record)
Conocyema Van Beneden, 1882 (basis of record)
Conocyema polymorpha Van Beneden, 1882 (basis of record)
Conocyemidae (basis of record)
Dicyema von Kölliker, 1849 (basis of record)
Dicyema gracile accepted as Dicyemennea gracile (Wagener, 1857) (basis of record)
Dicyema macrocephalum (Van Beneden, 1876) (basis of record)
Dicyema megalocephalum Nouvel, 1934 (basis of record)
Dicyema microcephalum Whitman, 1883 (basis of record)
Dicyema monodi Nouvel, 1934 (basis of record)
Dicyema moschatum Whitman, 1883 (basis of record)
Dicyema paradoxum von Kölliker, 1849 (basis of record)
Dicyema rondeletiolae Nouvel, 1944 (basis of record)
Dicyema schulzianum (Van Beneden, 1876) (basis of record)
Dicyema typus Van Beneden, 1876 (basis of record)
Dicyemennea Whitman, 1883 (basis of record)
Dicyemennea eledones (Wagener, 1857) (basis of record)
Dicyemennea gracile (Wagener, 1857) (basis of record)
Dicyemennea lameerei Nouvel, 1932 (basis of record)
Dicyemida (basis of record)
Dicyemidae van Beneden, 1882 (basis of record)
Heterocyemida (basis of record)
Intoshia Giard, 1877 (basis of record)
Intoshia leptoplanae Giard, 1877 (basis of record)
Intoshia linei Giard, 1877 (basis of record)
Intoshia major Shtein, 1953 (basis of record)
Intoshia paraphanostomae (Westblad, 1942) (basis of record)
Mesozoa accepted as Dicyemida (basis of record)
Microcyema Van Beneden, 1882 (basis of record)
Microcyema gracile (Wagenar, 1857) accepted as Dicyemennea gracile (Wagener, 1857) (basis of record)
Microcyema vespa Van Beneden, 1882 (basis of record)
Orthonectida (basis of record)
Pelmatosphaera Caullery & Mesnil, 1904 (basis of record)
Pelmatosphaera polycirri Caullery & Mesnil, 1904 (basis of record)
Pelmatosphaeridae Stunkard, 1937 (basis of record)
Pleodicyema Nouvel, 1961 (basis of record)
Pleodicyema delamarei Nouvel, 1961 (basis of record)
Pseudicyema Nouvel, 1933 (basis of record)
Pseudicyema truncatum (Whitman, 1883) (basis of record)
Rhombozoa (basis of record)
Rhopalura Giard, 1877 (basis of record)
Rhopalura elongata Shtein, 1953 (basis of record)
Rhopalura gigas (Giard, 1877) (basis of record)
Rhopalura granosa Atkins, 1933 (basis of record)
Rhopalura intoshi Metchnikoff, 1881 (basis of record)
Rhopalura linei (Giard) accepted as Intoshia linei Giard, 1877 (basis of record)
Rhopalura litoralis Shtein, 1953 (basis of record)
Rhopalura major Shtein, 1954 accepted as Intoshia major Shtein, 1953 (basis of record)
Rhopalura metschnikowi accepted as Intoshia metchnikovi (Caullery & Mesnil, 1899) (basis of record)
Rhopalura murmanica Shtein, 1953 (basis of record)
Rhopalura ophiocomae Giard, 1877 (basis of record)
Rhopalura pelseeneri Caullery & Mesnil, 1901 accepted as Rhopalura pelseneeri Caullery & Mesnil, 1901 (basis of record)
Rhopalura philinae Lang, 1954 (basis of record)
Rhopalura pterocirri de Saint-Joseph, 1896 (basis of record)
Rhopalura variabili Alexandrov & Sljusarev, 1992 accepted as Intoshia variabili (Alexandrov & Sljusarev, 1992) (basis of record)
Rhopaluridae Stunkard, 1937 (basis of record)
Stoecharthrum Caullery & Mesnil, 1899 (basis of record)
Stoecharthrum giardi Caullery & Mesnil, 1899 (basis of record)
Stoecharthrum monnati Kozloff, 1993 (basis of record)

Arctic Ocean for Intoshia major Shtein, 1953 
Arctic Ocean for Rhopalura elongata Shtein, 1953 
Arctic Ocean for Rhopalura litoralis Shtein, 1953 
Arctic Ocean for Rhopalura murmanica Shtein, 1953 
Arctic Ocean for Rhopalura variabili Alexandrov & Sljusarev, 1992 
European waters (ERMS scope) for Ciliocincta julini (Caullery & Mesnil, 1899) 
European waters (ERMS scope) for Dicyema megalocephalum Nouvel, 1934 
European waters (ERMS scope) for Dicyema monodi Nouvel, 1934 
European waters (ERMS scope) for Dicyema paradoxum von Kölliker, 1849 
European waters (ERMS scope) for Dicyema typus Van Beneden, 1876 
European waters (ERMS scope) for Dicyemennea eledones (Wagener, 1857) 
European waters (ERMS scope) for Dicyemennea lameerei Nouvel, 1932 
European waters (ERMS scope) for Intoshia leptoplanae Giard, 1877 
European waters (ERMS scope) for Intoshia linei Giard, 1877 
European waters (ERMS scope) for Intoshia major Shtein, 1953 
European waters (ERMS scope) for Intoshia paraphanostomae (Westblad, 1942) 
European waters (ERMS scope) for Microcyema vespa Van Beneden, 1882 
European waters (ERMS scope) for Pelmatosphaera polycirri Caullery & Mesnil, 1904 
European waters (ERMS scope) for Pleodicyema delamarei Nouvel, 1961 
European waters (ERMS scope) for Pseudicyema truncatum (Whitman, 1883) 
European waters (ERMS scope) for Rhopalura elongata Shtein, 1953 
European waters (ERMS scope) for Rhopalura gigas (Giard, 1877) 
European waters (ERMS scope) for Rhopalura granosa Atkins, 1933 
European waters (ERMS scope) for Rhopalura intoshi Metchnikoff, 1881 
European waters (ERMS scope) for Rhopalura litoralis Shtein, 1953 
European waters (ERMS scope) for Rhopalura metschnikowi 
European waters (ERMS scope) for Rhopalura murmanica Shtein, 1953 
European waters (ERMS scope) for Rhopalura ophiocomae Giard, 1877 
European waters (ERMS scope) for Rhopalura pelseeneri Caullery & Mesnil, 1901 
European waters (ERMS scope) for Rhopalura philinae Lang, 1954 
European waters (ERMS scope) for Rhopalura pterocirri de Saint-Joseph, 1896 
European waters (ERMS scope) for Rhopalura variabili Alexandrov & Sljusarev, 1992 
European waters (ERMS scope) for Stoecharthrum giardi Caullery & Mesnil, 1899 
European waters (ERMS scope) for Stoecharthrum monnati Kozloff, 1993 
Mediterranean Sea for Conocyema polymorpha Van Beneden, 1882 
Mediterranean Sea for Dicyema macrocephalum (Van Beneden, 1876) 
Mediterranean Sea for Dicyema microcephalum Whitman, 1883 
Mediterranean Sea for Dicyema moschatum Whitman, 1883 
Mediterranean Sea for Dicyema paradoxum von Kölliker, 1849 
Mediterranean Sea for Dicyema rondeletiolae Nouvel, 1944 
Mediterranean Sea for Dicyema schulzianum (Van Beneden, 1876) 
Mediterranean Sea for Dicyema typus Van Beneden, 1876 
Mediterranean Sea for Dicyemennea eledones (Wagener, 1857) 
Mediterranean Sea for Dicyemennea gracile (Wagener, 1857) 
Mediterranean Sea for Dicyemennea lameerei Nouvel, 1932 
Mediterranean Sea for Microcyema vespa Van Beneden, 1882 
Mediterranean Sea for Pleodicyema delamarei Nouvel, 1961 
Mediterranean Sea for Rhopalura intoshi Metchnikoff, 1881 

 Diet

 for Rhopalura pelseeneri Caullery & Mesnil, 1901

Parasitic in polychaetes and nemertines [details]

 Distribution

 for Dicyema microcephalum Whitman, 1883

Mediterranean; in cephalopods [details]