IN CERTAIN LEPIDOPTERA. 305 



tlmlate point, and a deep angular keel. Its summit is crowned with an erect ridge of 

 stiff hair, pointing slightly forward (fig. 23). 



The scaphium is more than ordinarily developed, and it presents some peculiarities 

 so suggestive that I bestowed upon it more than usual attention. The mass of flesh, of 

 conspicuous whiteness, and glistening at all its prominences, occupies almost one third of 

 the volume of the visible cavity. The keel is deep and ample, though thin ; it is much 

 excavated, the surfaces full of irregular hollows, with slender threads, and isthmuses 

 of white connecting flesh stretching across ; the hollows are more or less tinged with 

 black, and of a minutely granular surface. 



The " double teeth" attain here a development to which I have observed no parallel*. 

 They are seated in the usual place, on the summit of a great rounded mass of polished 

 flesh, which swells out on each side (fig. 22) from beneath the base of the tegumen, 

 gradually becoming of a deeper and deeper hue, apparently more and more chitinous, 

 until the colour merges into the glistening black of the teeth. Of these the principal 

 — which one can scarcely help calling the anterior (though it is strictly the posterior), 

 being next to the point of the uncus — is a broad, curved, acute spoon, cut on both its 

 edges, and also on Us bowl, with stout serne. The other tooth, equally tall, but 

 slenderer, curved in the same direction, viz. toward the base, is similarly serrated on 

 several lines. The whole space between the two teeth is a continuation of the spoon- 

 bowl, and is everywhere studded with sharp points. It is strange that most, if not all, 

 of the serrations are surmounted each by a stiff golden bristle, which seems likely to 

 interfere with their effectiveness f ; but the number of pale-yellow body-scales clinging 

 to all parts of these notched teeth show that they have done duty as prehensors. 

 Certainly, viewed in sunlight under the compound microscope, they are formidable 

 weapons to look at. 



At its very base, where it springs from under the deep keel of the uncus, the scaphium 

 forms a globose knob, skull-shaped, which is shining brown. But for this, and the tooth- 

 knob, and the cavities of the keel, the whole scaphium is brilliantly white, reflecting 

 the sunlight like the albumen of a boiled egg. The lower portions, both of cheeks and 

 keel, run obliquely downward and abdomenward in strong longitudinal folds. 



I know of no species in which the scaphium can be so effectively studied as this. 

 Yet I am compelled to confess an humbling uncertainty of its function. I carefully dis- 

 sected away the surrounding parts, and found this white organ to be firmly connected 

 with the chitinous base of the uncus (that is, with the eighth segment), and, apparently, 

 with a tube proceeding from the mass of convoluted yellow tubes which lie immediately 

 behind, which I suppose to be the biliary vessels of the colon. The orifice, however, is, 

 so far as I am able to judge, not at the extremity of this organ, as described by llerold 

 (if this indeed is his Tricmgelstuck, as I presume), but in the middle of the upper part of 

 its very basis, where it is united with the uncus. Projecting thus between the uncus and 

 the penis, we might call the scaphium a process from the perinaeum. 



* But sec P. Demoleus, p. 313, infra. 



f These great spoon-teeth are thus clearly identified with the aristate cheeks in 0. Remus, &c. 



SECOND SEKIES. — ZOOLOGY, VOL. II. 43 



