286 THE entomologist's record, 



to the end of the scaphium, but beneath it. There is no definite 

 lOfch sternite. (See Plate x.) 



I have not tried to make any exhaustive search, but the few 

 continental authorities I have looked into seem to have taken the 

 same view that I did, that the scaphiion was a sub-anal process, as, for 

 instance, Spuler's Hofmanu, not itself an authority, but to a threat 

 extent a summary of authorities. One of the exceptions is apparently 

 really more in error than the others, viz., Hermann Stitz, " Genital- 

 apparat der Mikrolepidopteren," in the ZouloijlHclw Jahrhnch 1900, 

 who makes the supra-anal " stuck " the scaphium, but unfortunately 

 calls the sub-anal ^' stuck" the uncus. In fact he still places the 

 uncus and scaphium one above and one below the anus, but reverses 

 the names. Pierce very accurately describes the position of the 

 scaphium [Genitalia of the Noctnidac, p. 13): "Attached to the anus on 

 the upper surface is a process present in some only of the Koctuidae, 

 which is The Scaphium (of Gosse)." 



This is a marked instance of description being better than a figure ; 

 the description is accurate and complete ; the figure shows the 

 scaphium as entirely apart from the anal tube, and in fact similarly 

 situated to an unnamed process present in some Xatodontida/'. [See 

 Plate xi.) 



The anal opening is usually on the level of the floor of the cavity ; 

 the usual exception is when a scaphium is present ; in that case there 

 is a projecting anal tube, as Pierce shows. The projection is main- 

 tained by the scaphium being a solid chitinous rod or plate along its 

 dorsal surface. In Acroni/cta tridens, for example, it is a simple, 

 slight, straight rod. In FajiiUo its upper surface is variously developed 

 in complicated fashion, and there often appears to be a development 

 beyond the point to which it is attached to the anal tube, the anal 

 opening being then some way from the extremity. I have not, how- 

 ever, examined species enough to have satisfied myself of anything 

 beyond the general fact, that the scaphium in I'apilio is more or less 

 attached to the upper surface of the anal tube. 



There is another case in which the anus is at the extremity of a 

 projecting anal tube. Here the supporting chitinous piece is not on 

 the dorsal surface of the tube as the scaphium is, but beneath it, and 

 would be entitled to Pierce's name of suhscaphiiiui. This structure 

 occurs in Hijdrocampa nymphaeata, I'tilodontis palpina, etc. I believe 

 all other cases of a projecting anal tube, i.e., without chitinous 

 support, are temporary if in the living animal, the result of pressure if 

 in preparations. 



It is perhaps merely the result of the few specimens I have examined, 

 perhaps of a defect of memory, but I do not remember to have seen a 

 well-developed scaphium in any species in which the 10th abdominal 

 sternite was well in evidence. These two structures being therefore 

 certainly rarely, possibly never, associated, no doubt accounts for the 

 name scaphium having been so generally applied to the 10th sternite. 



The scaphium is indeed not a very common structure, it occurs in 

 some Xoctuae, as for example Acronycta tridens, where it is a very 

 simple, delicate, straight rod along the dorsal aspect of the anal tube, 

 in Mainestra persicariae it is notably developed ; the 10th sternite, if 

 ever present in Xoctuae, is very rare, though the scaphium is not often 

 very distinct. 



