363 



lessened, the concentration to spider-like figures filling in the 

 interveinal cells, especially the three cells 3 to 5, at the inner 

 side of the internal row of spots, perfectly agrees with what is 

 found in V. urticœ. This is likewise the case with the diagonal 

 bar, the v -shaped top of the middle cell and the course of the 

 wing-veins being marked by transverse stripes of black pigment. 



Wing-sheath of Papilioxid.î:. 



Turning our attention to the Papilionidœ, we meet a highly 

 instructive object in the black and yellow variety of the pupa 

 of Papilio machaon (fig. 5). In this the amount of dark pigment 

 is much more considerable than in the green variet}-, and so its 

 distribution can easily be studied. It is noticed at a glance that 

 the same arrangement prevails as in the Vancssidce : the pig- 

 ment is partly concentrated along the course of the wing-veins, 

 the rest filling in the interveinal wing-cells. The former has 

 •especially accumulated along the inferior discocellular vein 

 and the bases of the four marginal veins radiating from it. The 

 V-shaped top of the middle cell is likewise present, though the 

 V is not nearly so well defined as in the Vanessidœ. Unlike 

 the pigment of the veins, which diminishes towards the outer 

 edge of the wing, that of the interveinal spaces goes on increasing, 

 thereby causing a dark marginal fringe to be present along 

 this border. It is easily seen that this fringe is composed of 

 as many triangular spots as there are interveinal marginal 

 spaces. The triangles even show a darker central part springing 

 from a light spot in the middle of the basis. 



These spots remind us, in respect of place and aspect, of 

 the outer series in Vanessidce, the inner series, on the contrary, 

 not being \-isible in P. Diachann. 



Another feature distinguishing the Papilionida- from the 

 Vancssidce. is the occurrence of a second marginal series of 

 spots, alternating with the first and therefore situated at the 

 ■end of the wing-veins. These latter spots are somewhat larger 

 and m()re convex than tlu' intt-rxeinal ones, and conseijuently 

 a])pt.ar raised abo\'e the wing-surface as brilliant lens-like 

 knobs. In a few other species of Papilionidcc, whose dried 

 pupic stood at my disposal, the lustre and size of these knobs 



