The empodium of the foot of specimens of Heterosminthurus bears a prominent lamella. In Heterosminthurus insignis, the longest setae on the inner side of the dens are about the same length as the mucro. In males, some of the setae between the eyes are longer than the others (Fig. 1).
Heterosminthurus insignis is a uniform yellow colour. The species is moderately common but has apparently not been recorded yet from Ireland or Wales.