276 ME. P. H. GOSSE ON THE CLASPIXG-ORGAXS 



into an elevated ridge, which is thinned off to an edge, and is then cut into a number of 

 parallel erect membranous points or bristles. When the double teeth are wanting this 

 aristate crest appears to supply their place, as in several of the Omithoptera ; but yet 

 occasionally both are seen, and then the arista? are more baseward — Hrechtheus. 



But the most remarkable form of the scaphium known to me is that of Merope, in 

 which the teeth are stout, broad, and most elaborately notched and bristled on their 

 edges ; for the details of which, with other points of interest, I must refer to my account 

 and figures of the species, ut infra. 



The lower parts of this organ are obscure, descending and receding towards the abdo- 

 men. Sometimes it is patent that the descending rami do certainly embrace the basal 

 region of the penis, and appear to unite again below it, but are not, I think, organically 

 united with it — e.g. O. Amphrysus, P. Rhetenor, Bathyoles, Agamemnon. But such 

 connexion of the scaphium with the penis cannot by any means always be affirmed. 



The usual appearance of the organ is opaque white, smooth, shining, like polished 

 ivory, often very pure, particularly the keel. Sometimes, however, it becomes partially 

 or even wholly pale, or even dark, hrown — Podalirius, Zalmoxis, Lycidas, JIacedon — 

 as if the chitinous element pervaded it, which microscopic examination confirm-- . 



By the same test the substance appears to be mainly muscular — a conclusion to which 

 I had already come from the armature of the double teeth. It was impossible to look 

 upon those formidable weapons, in Merope, for example, without inferring that the 

 compact mass upon which they are seated must be muscular, or they would be useless. 

 But I suspect that in this organ reside the muscles which move the uncus — perhaps also, 

 at least in part, the valves and the harpes, for which offices they would need to be 

 vigorous and massive. 



Many modifications of the form and conditions of the organ occur in different species, 

 which will be described seriatim f. 



On the nature, or even the existence, of the scaphium, I have little help from my 

 predecessors. Herold, in Pieris BrassicceX, does not distinguish it from the uncus, 

 which I find quite distinct, both being present, but contiguous. He, however, con- 

 founds the two organs under the name of the triangle-piece (" Triangelstuck "), which 

 he cites from De Geer. The minute projection from beneath the point, which he takes 

 to he the end of the rectum, is surely the keel of a small scaphium. The anus is, as I 

 believe, in the middle of that transverse line at which the muscular base of the scaphium 

 is united to the palate-like under side of the uncus §. (See P. Arcturus.) 



* The scaphium of P. Machaon, macerated and torn from its uncus, showed, at the upper part (the gunwale), a clear 

 yellow-brown tissue, with smooth edge, and minute bristles growing from the surface. This ran off into colourless 

 transparent tissue, decidedly fibrous, several of the bundles being formed of longitudinal fibres, which were more or 

 less covered with thin lamince filled with excessively minute but perfectly distinct regular parallel oblique strur. 



t For some further researches into the structure and relations of the scaphium, made after this memoir was 

 handed in, I beg to refer to the account of Omiihoptera Remus, infra. 



X Entwickelung der Schmett. xiii. tab. iv. figs. 3-6. 



§ The fact that the uncus is tubular, as may be clearly seen when it is forcibly broken across, suggested the 

 thought that perhaps itself might be the termination of the intestine. But very exact and repeated examinations 



