IN CERTAIN LEPIDOPTERA. 315 



points. The penis is somewhat thick, moderately long, blunt-pointed, turgid, the white 

 pulpy tissue copious. 



At fig. 11 these organs are represented as viewed sidewise, the surfaces having been 

 denuded of the copious scales and hair-scales, and both the valves removed. At fig. 12 is 

 shown the corneous skeleton of these regions. By one of those fortunate accidents uf 

 which an observant scient is always so glad to avail himself (as he can never command 

 them) a specimen of P. Erithonius, which had been badly infested with mould, came to 

 pieces in my hand, and the terminal segment dropped away from all the debris, clean, 

 just as I have sketched it at fig. 11. Here I saw not only the uncus terminating the final 

 segment, and the scaphium attached to it beneath, but, lower down, the orifice for 

 the extrusion of the penis, pierced through the middle of a vertical curtain of very 

 thin horny chitiue, which is suspended in place, by attachments on each side, to the 

 lower parts of the dorsal arch of the eighth (?) segment, as well as by two perpendicular 

 ligaments below, which tie it fast, the one to the middle of the ventral arch of the ninth, 

 the other (wider and thinner) to that of the eighth segment. 



Perhaps — since I have never met with any thing like this structure, before or since — 

 it may not be impertinent to add that I have not exercised my imagination upon a 

 piece of integument irregularly pierced and fractured ; the screens, the orifices, and their 

 edges were quite symmetrical and smooth, exactly as I have represented them ; and this 

 chitinous curtain is still in my possession, in excellent preservation. 



Papilio Ancuisiades, Esp. (Plate XXXI. figs. 13-15.) 



Valve nearly parallel-sided, bluntly arched at the tip ; margins furnished, more or less 

 completely, with a narrow fringe of hair-scales. The cavity is abruptly depressed a little 

 way within the margin on each side. Just at the very edge of the descent, on the dorsal 

 side, I observed in one specimen two minute black teeth curving towards the cavity ; but 

 of these I could find no trace in other specimens. 



The harjpe is a thin concave plate, long, narrow, parallel-sided, seated within the 

 depression, but not reaching either of its margins. It can be easily lifted unbroken and 

 laid on a slip of glass ; and is then seen to have a continuous floor of yellow chitiue, 

 excessively thin, and yet apparently of two surfaces, since the unequal contraction 

 of drying has raised irregularly ramifying, thickened, fine lines, meandering like rivers on 

 a map ; Avhile the bounding lines, and the upper part of the arch produced by their 

 meeting, are of a deep, rich, yellow-brown hue, gleaming and glittering in the changing 

 light, like cut glass. The abrupt termination of this darker part of the arch, within, 

 conveys the idea of an overhanging edge : but this is delusive ; for, by careful mani- 

 pulation under the microscope, I proved that this etfect is produced merely by increase 

 of density. The point of the arch is a long taper tooth ; and three or four teeth on each 

 side descend along the outer edges of the arch. But the minuter details of number and 

 order are not constant in different examples. The dark tooth-like objects which I have 

 represented within the point, directed inward, are not true teeth projecting from the 

 chitinous surface ; for, though they appeared exactly as I have drawn, yet when I slowly 

 and carefully tilted the object under the microscope, so as to obtain changing angles of 



