298 ME. P. H. GOSSE ON THE CLASPING-OEGANS 



tubular rod, with a hatchet-shaped tip heut-over dorsally. But, separating it from the 

 membrane of the valve (to which it adheres somewhat tenaciously), we find that the 

 end, which stands obliquely erect from the plane of the valve, is broadly semicircular 

 in outline, and that this outer edge is serrated with delicately formed but sufficiently 

 strong spine-like, acute teeth (as seen in PI. XXVIII. fig. 18.). 



The uncus is long, slender, wiry, curved to one fourth of a circle, clothed along the 

 median line of its summit with a ridge of erect black hairs, tall at the base and dimi- 

 nishing to nothing near the point ; the point a small blunt spathula ; the under surface 

 a narrow keel of uniform depth. 



Scaphium little developed in its white fleshy portion, but well in its horny arma- 

 ture; two black, shining, upcurvcd, stout teeth projecting from the extremity, each 

 with a low conical knob behind it. Between these, the usual fleshy keel is represented 

 by a narrow plate of shining brown chitine ; and true keel there is none*. 



The penis, of ordinary form and size, projects from the very bottom of the cavity, 

 leaving a great vacant space between it and the scaphium. 



Papilio Schmeltzi, Herr.-Schaff. (A. D.) (Plate XXVIII. figs. 20-22.) 



Voire rather small, pointed ; the narrow hair-like black clothing-scales of the 

 exterior projecting beyond the margins slightly and raggedly. Cavity shallow. 



llarpc a chitinous ridge (or thin blade set edgewise) of rufous hue, which runs through 

 the length of the valve (PI. XXVIII. fig. 20, right valve) in a sigmoid line, not 

 separable from it without tearing. It does not appear to dilate into a lining plate 

 throughout its length. The base spreads like that of a tree-trunk. At the lower curve 

 of the ridge is projected a stout triangular tooth ; and the extremity dilates into a broad 

 axe-shaped blade, somewhat thick, as if the axe were unfamiliar with the grindstone. 

 The dorsal side of the ridge is fringed with a line of stiff hairs. 



In these observations I have several times fancied a slight difference in the armature 

 of the two valves of the same individual t- In this example it was quite manifest; for 

 in the left valve (fig. 21), the sigmoid curve was very much slighter; the lower knob 

 was more produced, and more decidedly a tooth, bent-over dorsally; and the securiform 

 head differently shaped, itself approaching the form of a broad tooth ; both projecting 

 towards the dorsal side at an angle of about 15° with the floor of the cavity. There is, 

 too, a secondary ridge, very evanescent, running down from the point toward the dorsal 

 margin of the valve; and a third ridge, which seems not connected with the harpe, 

 running through the length of the valve, centrally. 



Up to this point my observation had left the impression that the machinery seemed 

 inefficient in this species; the rounded outline and blunt edge of the "axe-head" 

 seemed incapable of any seizing or holding function, like that of the sharp points with 

 which I had become familiar in these elaborate harpes. But, on submitting it to an 

 increased magnifying power, viz. of 140 diameters, the " axe " assumed a quite different 

 aspect. Now the edge was seen to be studded closely (see fig. 22) with minute, acute, 



* But this needs reexamination. 



t See the Memoir by Messrs. Scudder and Burgess, cm Asymmetry in the Hesperiada 1 , in Proc. Boston Hoc. 

 Nat. Hist, for April, 1870. 



