Key Position: 20 Back to (19a)
20 a. Test broader than long, fundus conical, a constriction forms a broad collar under the wide aperture.

SEE Figure 20-1

 20 b. Test spheroidal, fundus rounded to acuminate, short neck attached to recurved or straight collar.

Proceed to 21

FIGURE 20-1

Difflugia bacillaliarum Perty 1849
Difflugia bacillaliarum PERTY 1849, p. 27
Difflugia bacillaliarum Perty MEDIOLI and SCOTT 1983, p. 20-21, pl. 5, figs. 16-19, pl. 6, figs. 1-4
Specimen from Lake Erie, Ontario.