(i) Disc-pores: each disc-pore has a central loculus which is usually round but may be oval, surrounded by a number of similarly-shaped loculi or pores, the complete disc-pore looking rather like a wheel with spokes. Each disc-pore usually has 5-10 loculi in the outer ring and the pores are therefore known as multilocular disc-pores. Multilocular disc-pores can be divided into two groups: the pregenital disc-pores and the spiracular disc-pores.

(a) Pregenital disc-pores: are primarily located on the pregenital segment VII, thus the name. However, on most genera, they are also found across some of the more anterior abdominal segments and, less frequently , medially on the thorax and head (where they are referred to as multilocular disc-pores).

(b) Spiracular disc-pores: are in bands in the stigmatic furrows between the stigmatic area on the margin and the spiracles.

(ii) Ventral microducts: the oval, sclerotised pore of each ventral microduct is located at the base of a short, outer ductule (longer than that of the dorsal microductules). The pore opening is across the widest part of the pore and the non-staining inner ductule is usually broad and skirtlike, not filamentous.