311 MR. P. II. GOSSB ON THE CLASPING-OEGANS 



Papilio Agamemnon, Linn. (Plate XXXI. figs. 0-8.) 



Valve small, sliort, rotundo-triangular, fringed with long hairs, not very dense. There 

 is a broad, fiat shelf, going nearly all round, except at the base; this shelf is beset with 

 stout but short hairs, which bend over the inner edge; and the very edge itself is fringed 

 with short stiff bristles, almost like spines. 



At the base of the cavity lies the harpe, a shallow cup of chitine, thickened around 

 the edge, and slightly free ; on its dorsal side it rises into a tooth-like lobe of thin but 

 dark brown chitine, of rotundo-triangular outline, which docs not appear to be serrated 

 (PI. XXXI. fig. G). 



The circumference of the abdominal cavity is densely set with projecting hair-scales, 

 which in particular rise from the summit of the ultimate segment to its very point, and 

 then, arching forward, form a long horizontal thatch. When these hairs are detached 

 (as. in part, at fig. 7), the point, ordinarily the uncus, is seen to be short and slightly bent 

 upward, and, viewed vertically fas at tig. 8), to be truncate, and even very slightly bifid 

 at the tip. Below, there is a well-formed but very small scaphium, with no armature; 

 and then a penis of much slenderness, and so long thai its point protrudes from between 

 the valves, when these are closed. The chitinous portion is downward, ends in a point of 

 greal tenuity, and forms an imperfeel tube with arching edges above, within which, 

 prominent near the tip, is a pulpy white tissue. The sheath of laminae descending from 

 the scaphium is conspicuous and shaped like an elegantly pointed leaf on each side, 

 united below. 



Papilio Erithonius, Cram. (Plate XXXI. figs. 9-12.) 



Valve of an outline somewhat trapezoidal, with the angles rounded, the terminal 

 angle produced, sometimes truncate, and ending in three small obtuse lobes. A fringe 

 of hair-scales beyond the margin on the dorsal side only; the floor of the cavity, 

 where it is not covered by the harpe, having a cloth-like surface, unusual. 



Nearly allied, as this Indian butterfly seems, in form and colouring of the wings, to the 

 African P. Demoleus, there is no resemblance in the appearance of its valve (see PI. XXX. 

 fig. 25). Nor is there any more in its harpe ; for this organ is a shallow cup of chitine, 

 quite rilling and accurately fitting the basal half (and more) of the valve-cavity, having its 

 ventral edge thickened, and the dorsal rising into a thin chitinous wall, of considerable 

 height, the summit of which is serrated with sharp teeth (PL XXXI. fig. 9). When 

 this harpe is carefully separated from the lining-membrane of the valve, it is seen to 

 be less simple ; for the elevated dorsal lobe is now seen to consist of three parallel 

 lamina?, which are of various lengths and heights, of which the inmost (also the tallest) 

 alone is serrated. 



In the abdominal apparatus there is a general agreement with the Merope and 

 Demoleus pattern, with considerable diversity in detail. The uncus is short, little curved, 

 ending in a broad and thick spathulate point, the keel deep, the rami rapidly receding, 

 rising above the level of the summit, and forming a wide triangular arched roof to the 

 cavity. The scaphium is minute, but possesses the essential features ; the " double tooth " 

 on each side is well marked ; the frontal keel, however, is replaced by two erect fleshy 



