• Calvertina Ludlow, 1909 (uncertain)
• Calvetina Canu, 1908 †
• Calvezina de Civrieux & Dessauvagie, 1965 †
• Camerina Bruguiere, 1792 † accepted as Nummulites Lamarck, 1801 [Class: Globothalamea]
• Camerina Rafinesque, 1815 (unaccepted > nomen nudum) [Class: Protozoa (awaiting allocation)]
• Cancerina Scott, 1901 accepted as Selioides Levinsen, 1878
• Carcerina E.M. Fries, 1849 accepted as Diderma Persoon, 1794
• Carderina (Cassini) Cassini in F. Cuvier, 1827 accepted as Senecio Linnaeus, 1753
• Carterina Brady, 1884 [Family: Carterinidae]
• Carterina Waagen & Wentzel, 1888 † accepted as Carta Stechow, 1921 † [Family: Stromatoporida (awaiting allocation)]
• Catherina Lepesme & Bruening, 1955 (uncertain)
• Cayerina Kishida, 1927 accepted as Kiricephalus Sambon, 1922
• Claverina Navás, 1913 (uncertain)
• Cuvierina Boas, 1886