 The genital operculum (a plate-like segment which contains the genital aperture) of "Herefordopterus" was composed by two fused opercular segments posterior to the deltoid plates (two small plates above the genital appendage), which are more clearly expressed in the type B specimens (assumed to be males).It was ornamented with prominent scales.The telson (the most posterior segment of the body) was wide anteriorly posteriorly tapering to a lanceolate shape with a keel.