_Remarks._—This species exhibits a large amount of simple variation, in the presence or absence of a pale patch on the uppers, in the brown submarginal marks on the lower wings, in the form and extent of the yellow band, and in the size of the specimens. The most extreme forms, as well as the intermediate ones, are often found in one locality and in company with each other, indicating that over the above range continual intermixture probably takes place, and thus prevents any one form from becoming specialized in a restricted area. The two following modifications of it, however, have acquired perfect stability, each in a large island situated on the extreme limits of the species. I therefore consider them to be distinct, though the actual differences are but small. 53. PAPILIO PERTINAX, n. s. Tab. V. fig. 4 (♂). _Upper side_: anterior wings rather more elongate and pointed than in _P. Severus_, dusky brown, with faint longitudinal rows of yellow scales in the cell, and with rather denser scales between the nervures beyond it; these are condensed into a narrow yellowish band parallel to the outer margin, and rather nearer to the cell than to it. Hind wings black, with three yellowish white subquadrate spots (the upper one smallest) situate between the outer angle and the discoidal nervule; beyond these and continued to the anal angle are a few very faint and minute groups of scales. _Under side_ as above, but the transverse band on the upper wings is whiter, and on the lower wings are seven submarginal brownish-yellow lunules, the middle ones least marked, and those at the outer and anal angles having above them a very small group of minute blue scales. The female is paler-coloured, with the markings rather more diffused, and has on the under side an imperfect ocellus at the anal angle, a row of faint brown lunules extending to the three white spots, and two irregular lunules of blue atoms below those next the abdominal margin. Expanse of wings, ♂, 4¼ inches; ♀, 5 inches. _Hab._ Macassar (Celebes) (_Wall._). _Remark._—This species was rather abundant near Macassar, in woody places, and was very constant in its markings and general aspect. 54. PAPILIO ALBINUS, n. s. Tab. V. fig. 5 (♂). Wings broader than in _P. Severus_, costa less arched, tail smaller, and the caudal margin less produced. _Upper side_: brown-black; anterior wings with very faint horizontal lines of yellowish scales in the cell; apical portion of the wing more thickly powdered between the nervures, the powdering fading away towards the outer angle. Posterior wings with a large yellowish-white patch, commencing close to the anterior margin, widening in the middle so as to cross the end of the cell, and ending in a triangle with prolonged apex at the abdominal margin; the outer edge of this spot is regularly angulated and scalloped; two very faint brown lunules occur next the anal angle; and the outer margin is rather broadly white-edged between the dentations.