Just as Phylloscopus and Acanthopneuste have been bunched together by many systematists, though so different to one another in many ways, amongst others in their nidification, so Abroscopus (Abrornis auct.) and Seicercus have been both placed under the latter name. Yet the one has only ten and the other twelve tail-feathers, a structural difference accompanied by a wide difference in nidification and in the eggs laid by the two groups. Seicercus, as we have seen, always lays white unspotted eggs, Abroscopus equally invariably lays pink or pinkish eggs, densely spotted. The great difference in the nesting-habits will be seen in the following pages. The foregoing fines give my reasons for retaining Abroscopus as a separate genus.