"4.5. Calcarinoidea Calcarinids are characterized by trochospiral test and an elaborated canal system. Like nummulitids, they harbour diatoms as endosymbionts (Sen Gupta, 1999). Recent calcarinids were originally assigned to Rotalioidea and encompassed Calcarina but did not include Pararotalia and Neorotalia, which were classified in the Rotaliidae. Hottinger et al. (1991) revised the genera Pararotalia, Neorotalia and Calcarina and united them in the subfamily Pararotaliinae, based on the common possession of morphological features such as an umbilicus closed by a plug, interiomarginal extraumbilical apertures with a toothplate forming a spiral canal and septal flaps and intraseptal interlocular spaces. Molecular analyses, however, show that Pararotalia, Neorotalia and Calcarina clearly branch with members of the Calcarinidae (Holzmann et al., 2006, this paper)."