IN CEETAIX LEPIDOPTEEA. 321 



microscopic examination (see fig. 8), It is now perceived to be a broad concave plate, 

 rising into somewhat thicker Avails at the sides, and having an elevated thin ridge running 1 

 up in the midst. The "eagle's head " is very sensibly thickened, and abruptly, so as to 

 assume the semblance of a twofold wall of the tissue ; but very careful manipulation 

 has convinced me that this appearance is illusory. All over the thinner region meander 

 those irregular lines which I have noticed before, so much like rivers on a map, and 

 which I suspect are caused by the shri veiling of the investing tissue in drying. Besides 

 these, there are a few scattered bristles, each rising from a minute elevated knob or bulb. 

 The very edge of the "eagle's head" is a little arched-over; its line is uneven, but 

 I cannot detect any serration in any part. 



There is no trace of an uncus. The posterior margin of the upper arch of the eighth 

 segment, when viewed vertically (as at fig. 9), is nearly straight, or follows an uniform 

 slight curve, with no attempt at central projection. Immediately beneath its middle 

 is seen a small but distinct scaphium, with the "double tooth" strongly developed in its 

 principal member, black, long, nearly straight, horizontal, reaching to the extremity of 

 the scaphium, the secondary visible only as a low shining knob. The sides of the 

 scaphium are rounded, concave exteriorly ; and a very distinct thin white keel is below. 



Dr. Buchanan White, in his beautifully illustrated memoir, has given a vertical figure 

 of what he considers the tegumen of P. Podalirius (pi. lvi. fig. 39 b), which, in his text 

 (p. 361), he says is " almost bilobed." But I venture to think he has fallen into error 

 here, careful lateral examination showing that this structure proceeds from beneath the 

 straight edge of the tegumen, as I indicate at fig. 10. It is certainly, therefore, the sca- 

 phium, as the whole details prove. 



The penis consists of a blade of glittering black chitiue, folded longitudinally, and 

 ending in a slender finger-point, with a knob at its origin. Thus folded, the sheath does 

 not half contain the white pulpy portion that runs along apparently within it, and at the 

 tip expanded beyond the finger. Possibly in life the firm chitinous sheath is semi- 

 tubular, and takes this folded form by drying. It sheds some light on the curious appear- 

 ance of the organ in P. Codrus (infra). 



I have examined minutely two examples of this species, and find no appreciable differ- 

 ence in any of the organs observed. 



Papilio Latreillii, Don. (Plate XXXII. fig. 11.) 



Valve regular in outline, ovate, nearly equal-sided, pointed ; the exterior clad with a 

 dense coat of close-set scarlet hair-scales, which project, in an even thick fringe, beyond 

 the ventral margin throughout, but not sensibly on the dorsal margin, of which a few 

 black hairs only occupy the terminal moiety. Interiorly it is deeply and evenly hol- 

 lowed ; along the midst of the cavity runs an irregular-shaped harpe, adherent to the 

 lining-membrane (though readily detached), dilating into a broad blade of brown 

 chitine, serrated with minute teeth along its edge, and projecting a prominent angle at 

 each end. This blade is free, and stands up at an oblique inclination from the cavity. 



The intravalvular organs I have examined imperfectly, and only in situ. The uncus 



SECOND SERIES. — ZOOLOGY, VOL. II. 45 



