Polythalamous _Orthocerata_ Belemnites, Orthoceras, Cephalopoda Nodosaria, Hippurites, Conilites. _Lituacea_ Spirula, Spirolina, Lituola. _Cristacea_ Renulina, Cristellaria, Orbiculina. _Spherulacea_ Miliola, Gyrogona, Melonia, (Microscopic.) _Radiolacea_ Rotalites, Lenticulina, Placentula, (Micros.) _Nautilacea_ Discorbites, Siderolites, Polystomella, Vorticialis, Nummilites, Nautilus. _Ammonacea_ Ammonites, Ammonoceras, Turrilites, Baculites. Monothalamous Argonauta. Cephalopoda Heteropoda Carinaria. * * * * * TABLE OF THE CONCHOLOGICAL SYSTEM OF DE BLAINVILLE. Key. 1 = TYPE MALACOZOARIA 2 = SUB-TYPE MALENTOZOARIA CLASSES A = CEPHALOPHORA B = PARACEPHOLOPHORA DIOICA C = PARACEPHALOPHORA MONOICA D = PARACEPHALOPHORA HERMAPHRODITA E = ACEPHALOPHORA F = NEMATOPODA G = POLYPLAXIPHORA ORDERS a = Cellulacea b = Polyphalamacea c = Siphonobranchiata d = Asiphonibranchiata e = Pulmobranchiata f = Chismobranchiata g = Monopleurobranchiata h = Aporobranchiata i = Nucleobranchiata j = Cirrobranchiata k = Cervicobranchiata l = Scutibranchiata m = Palliobranchiata n = Rudistes o = Lamellibranchiata _Classes._ _Families._ _Genera._ _Orders._