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



Whatever its office, I infer it to be, in part at least, muscular, from its so often carry- 

 ing those remarkable weapons which I have called " double teeth." For, based on yield- 

 ing and non-contractile tissue, they would be ineffective and useless ; whereas their firm 

 chitinous substance, their depth of colour, and their high polish, indicating hardness, 

 and, as just described, their notched edges and acute points, all indicate vigorous and 

 definite action, dependent on strong muscular contraction. 



Nevertheless, I am bound to confess, the position of these weapons and their direction 

 just under the uncus do not seem the most favourable for the only function which we 

 can attribute to them, viz. copulative prehension. 



The penis is a straight, nearly horizontal column of brown clear chitinous substance, 

 moderately thick, not sensibly expanding, as usual, but rather diminishing to the extre- 

 mity, and ending in a linger-like poiut and irregularly lobed lips. I carefully removed 

 the walls of the abdominal segments, till I exposed the root of the cylindrical penis in a 

 mass of muscular tissue, just at the insertion of the sixth segment. 



Papilio Bruits, Fabr. (Plate XXIX. figs. 2i : 25.) 



The details that I have just been giving were from specimens labelled as having been 

 taken at Calabar, in West Africa ; and they agreed in markings, almost exactly, on both 

 surfaces, with the Merope of Cramer's plate 378. b, e. But I have examples of a style of 

 colouring that differs much from any that I have seen figured or described by authors. 

 These two males, ticketed P. Brutus, I purchased from a small collection made at Ellongo, 

 in Madagascar, arc distinguished by having the black spot at the anal angle of the hind 

 wing above very small, and the Avhole of the hind wing below, of a warm yellow-brown 

 hue, with an undefined light dash across the middle, and scarcely any trace of the dark 

 lines so conspicuous in the ordinary forms. 



Now, in these Madagascar examples, the harpe takes a form very different from that in 

 the continental P. Merope. The valve has much in common ; and so has the harpe, in its 

 plan ; but the serrated portion, which is marked off by abrupt dilatation, is reduced to a 

 small ovate blade at the very termination ; and the projecting arm is placed close 

 beneath it, is swollen in the middle, sinuately curved, and tapered to an acute point. 

 The staff is very long and slender, cylindrical, pale, shining, bending from the base to 

 the dorsal corner, sunken in a deep abrupt depression of the valve-cavity. The head or 

 blade is free, a thin oval plate of polished black chitine, brought to an edge all round, 

 and cut into strong saw-teeth, which are divided by grooves that run up into the area 

 of the blade. Just at the point where it adheres to the lining-membrane, there is an 

 angular expansion of the staff which sends off, nearly at a right angle, the polished taper 

 arm, in quite a different plane from that of the blade ; this is not serrated. 



This long sharp spine, and its fellow, stretch away on either side of the uncus, when 

 the valves are closed, and are doubtless effective prehensors ; whereas the short, blunt 

 arms, in Merope, placed so low down in the valves, one cannot well suppose to be of any 

 prehensile power. On the other hand, in Merope, the extent of serrated blade is greatly 

 superior. 



The abdominal organs are the same, essentially, in both. For though, in one speci- 



