Mayncinidae Loeblich and Tappan, 1985 (*1923), p. 92.

Test free, flattened to lenticular, planispirally enrolled, numerous broad and low cham­bers per whorl that may increase rapidly in breadth and may uncoil in the later stage; wall agglutinated, granular, and homogene­ous in appearance, without perforations or alveoles; aperture interiomarginal to areal, single or multiple. U. Jurassic (Kimmeridgian) to U. Cretaceous (Santonian); commonly in a carbonate shelf facies.

 

Remarks: Differs from the Haplophragmoididae in the flattened test with numerous chambers per whorl, rapid increase in height of the whorl, tendency to uncoil in the later stage, and the commonly multiple aperture. Differs from the Lituolidae in the large, len­ticular to flattened planispiral coil, and reduced, flattened uniserial stage and differs from the Charentiidae in the simple rather than canaliculate wall.