View source for File:Fig 83 th (2).gif

Model in polar view and a globular Alveolina (Middle (?) Eocene of Pakistan) cut in a similar direction. Note the shortened distance between the septa in the equatorial and the lengthened distance in the axial realm. In oblique sections of globular to elongate involute planispiral shells the structure of the chambers in opposite sectors of the section approaches more or less closely in appearance that of either an equatorial or an axial section depending on the location and angle of the cut with respect to the septa.