The categories are:    salinarius - lacking lateral and ventral tubules (Fig. 9)

                Lacking lateral tubules:
            halophilus - anterior VT very short or absent, posterior VT short (Fig. 8).
            bathophilus - short straight VT.
            fluviatilis - VT slightly curved and coming to a point at ends. (not known from Australia)
            thummi - anterior VT with 'elbows', posterior VT coiled (Figs. 6 & 7).

            Possessing lateral tubules:
            reductus - anterior VT very short or absent, posterior VT short.
            melanotus (sometimes called 'semireductus') - short straight VT.
            plumosus - anterior VT with 'elbows', posterior VT coiled (Figs. 4 & 5).