IX CERTAIN LEPIDOPTEEA. 277 



Neither Burmeister nor Siebold makes any allusion to the scaphium. De Haan's 

 slight mention of " lateral plates " has been already cited. From his figure, I suppose 

 he alludes to the scaphium, by this phrase. In the numerous figures of Dr. White's 

 Memoir *, minutely beautiful, and carefully executed, as these are, I find no trace of 

 the organ; and I think that probably it is peculiar, or nearly peculiar, to the true 

 Equites. I say " nearly peculiar," because, though Dr. White finds it not, as a separate 

 organ, in the European Pieridae, yet I hope presently to show that unequivocal traces 

 of it are to be found in certain members of the family. 



5. The Penis. 



This organ forms, strictly, no part of my subject, which is not the function of gene- 

 ration, nor the organs that perform it, but certain prehensile apparatus that are ancillary 

 to the performance. Yet, as this member is so essentially the centre around which the 

 whole apparatus waits and serves, and as it forms so conspicuous an object in the 

 accompanying designs, I can scarcely avoid giving some account, at least, of its varying 

 form and position. 



The penis is usually seen, when the valves are opened, in the lower half of the genital 

 cavity, in the form of a column, more or less cylindrical, varying much in diameter and 

 in length, projecting from the interior of the abdomen. In some instances it is so short 

 as not to appear beyond the walls of the eighth segment, e. g. Vertumnus, Lycidas; but 

 it is doubtless capable of being protruded, to a certain extent, by its proper muscles f . In 

 others it is so long that it cannot be contained within the cavity, but projects beyond 

 the margins of the valves when these are shut. In Merope, JJealecjon, Hesperus, Iihe- 

 teuor, the tip just reaches the edges of the valves, or exceeds them in a slight degree; 

 in Podalirias, Bromius, Macedon, and still more in Bathycles, the protrusion is remark- 

 able; but, in the Coon group, including the beautiful Rhodifer lately sent from Anda- 

 man, the penis projects from the hinder extremity to an extraordinary degree, like a fine 

 steel wire, that quite arrests the attention as we see the insect in a cabinet. No less 

 notable is the extreme slenderness, and, at the same time, the strength and elasticity, of 

 the organ in the just-mentioned species. 



As to position, the penis appears so high as almost to be in contact with the scaphium 

 — Tamils ; again, almost on the very floor of the cavity — Deipltontes ; and, in some 

 species or other, in every intermediate stage. 



have convinced me that the extremity of this organ is solidly ehitinous, and absolutely imperforate, at least in 

 0. Remus and 0. Haliphron. But, when the uncus is removed, there is clearly discerned, under the very middle 

 of the tegumen, a circular orifice leading from the abdomen into a groove, which is hollowed along the median line 

 of the scaphium-sulcus. In dried specimens the intestinal convolutions are reduced to an undistinguishable mass of 

 yellow dust. Yet, on one occasion, I detected (or fancied) a thread connecting the mass with the orifice just described. 

 It had, however, vanished in an instant. 



* Op. tit. 



+ In an abdomen of 0. Haliphron I carefully laid bare the penis till I traced the base of the chitmous cylinder 

 originating in firm muscular tissue, in the ventral arch of the seventh (that is, the ante-penultimate) segment. But 

 in P. Merope, I laid bare the cylinder to its base in muscular tissue, in the sixth, or even the fifth segment. 



