LINDSEY—ON GYPSINA PLANA CARTER, AND THE RELATIONS OF THE GENUS 47 
irregular in arrangement, shape and size, and while those chambers towards the outside 
of the knob are very similar in shape to those seen in a vertical section, the inner ones are 
irregularly polygonal. 

Fig. 3. Section through the centre of a knob, showing Fig. 4. Section showing the arrangement in the outer 
the irregular arrangement, shape and size of the layers of a knob or in a section at right angles to the 
chambers, also the perforated plates. x 96. surface in the ordinary thin part of the layer. x 75. 
The foramina occur not only in the walls seen in section, but also in those in the 
plane of the section, in which case the walls are seen as perforated plates. 

Wirt 
Fig. 5. Enlargement of portion of Fig. 4 to show the gaps in the walls of the chambers 
as well as the perforated plates. x 212. 
These perforations occur right up to the centre of the foraminifer, and not merely in 
the superficial layers as in Homotrema and Sporadotrema, and they are all of the same 
