In some armored species, a ventral pore may be present at the juncture of the first apical plate (1') and an anterior intercalary or another apical plate on the epitheca. Sometimes the pore is in one of the apical plates. The presence of a ventral pore or its placement may be diagnostic for certain species (Steidinger and Tangen, 1996).

Alternative form for ventral pore : ventral opening.