Its name refers to French entomologist, explorer and priest Xavier Montrouzier.

Smaller than all the forms of P. ulysses, both wings more strongly sinuous between the veins, the forewing beneath with yellowish grey transverse bar in the cell and crescents of the same colour as proximal bordering to the grey discal area; the submarginal spots of the hindwing darker yellow than in P. ulysses.

The number of the pilose stripes in the and the extent of the blue in male and female are variable.

The principal forms are: f. ulyssellus Westw., the blue reaches in the male to beyond the apex of the cell and completely encloses the small black discocellular spot; the pilose stripes are absent or feebly indicated, in the female the blue reaches to or nearly to the apex of the cell of the forewing.

westwoodi Oberth., the blue still more strongly reduced, the male with 4 or 5 rather broad pilose stripes.