As in all species of Pontia there is a slight wrinkling of the membrane in the interspaces, forming slight channels running from the outer border inward, nearly to the depth of two interspaces, indicated in the fossil by dark lines as heavy as the nervures, and caused by their filling with sedimentary material. The extreme length of the part of the wing preserved is 24mm. and the greatest width 22.5mm.
The markings lead one to conjecture that the individual was a male.
Body rather robust (Pl. III, figs. 9 and 10). Vertex of head large, broad, convex. Eyes pretty large, short ovate, their longer diameter vertical. Palpi (Pl. III, fig. 7) slender, resembling those of Thais, but rather longer, extending far beyond the eye, rather thinly clothed with hairs. Antennæ (Pl. III, fig. 8) resembling those of Sericinus more than those of Thais, being about half as long as the body, slender and equal on the basal three-fifths, gradually expanding beyond into a club, which is more than twice as broad as the stem, and stoutest just before the well rounded, slightly upturned tip; in the middle of the antennæ the joints are half as long again as broad, broader than long at the base of the club, and three or four times as broad as long in the middle of the club and beyond; on the apical half of the club, and perhaps a little further, the joints of the club are furnished with a double row of minute shallow pits, such as are seen in Eurymus. The tongue was at least as long as the thorax.
The thorax is well arched and pretty stout; the paraptera (Pl. III, fig. 6) are a little more than twice as long as broad, their outer edge nearly straight, the posterior extremity broad and well rounded. The legs are not well enough preserved to state anything concerning them with certainty, but the middle (?) pair are probably of the length of the antennæ.
The fore wings (Pl. III, fig. 3) are only a little more than half as long again as broad, the greatest breadth beyond the middle; the costal border is pretty regularly and not greatly arched throughout; the outer margin is more strongly arched but with a similar regularity, and the general direction of its upper half is at right angles to the outer third of the costal border, the apex scarcely rounded off; the inner border is nearly straight. The proportions of the hind wing, as to length and breadth, are nearly the same as those of the fore wings, making it unusually long and narrow, as in Thais (Pl. III, fig. 4), and also, as there, nearly as broad toward the base as at tip. The costal border is rather strongly convex next the base of the wing, but beyond is nearly straight, sloping apically so as to make a uniform curve with the outer border, which is almost entire as in Parnassius (Pl. III, fig. 5), rather than as in Thais (Pl. III, fig. 4), strongly arched, especially near the last median nervule, and angulated below where it meets with the regularly and broadly concave inner margin.