1902.] 155 



piece seen from above is split, the superior opening being filled with a short fringe- 

 shaped, slightly upturned lobe or valve, beset with long hairs. Vulvar scale 

 moderately long, no free side lobes ; sides of the segment produced into a distinct 

 anglo ventrally, the angle being followed dorsalwards by a distinct excision. 



The side blades of the internal apparatus are strong and well-defined, apex 

 obliquely truncate. Central triangular piece long and slender at the apex ; foot- 

 shaped piece 1 has the " heel " slightly broader than the fore part. 



A. STIGMATELLA, Zett. 



The 9th segment large, when viewed from above, pointed in the middle of the 

 posterior margin, but the segment in dry examples is not always easy to separate 

 from the tubular piece, which above is divided into two sections pointed at the apex, 

 the points being usually visible even in dry specimens. The vulvar scale has usually 

 the appearance of having the apex truncate, but the scale in these insects is very 

 slightly chitiuized, and the form may therefore vary a little ; the character, never- 

 theless, seems real. There are no side lobes. The sides of the segment seen from 

 beneath are slightly produced, the angle being followed by a shallow excision. 



In all the preparations the side blades are rather indistinct ; the central tri- 

 angular piece is elongated as in A. Wallengreni, while the foot-shaped piece has the 

 " heel " very narrow in all the preparations. 



A. MULIEBRIS, McL. 



The 9th segment is rather large ; when viewed from above the margin iB 

 rounded ; the tubular piece from the same point of view is usually only visible as a 

 little rounded process. 



The vulvar scale has a prominent middle lobe, but I am unable to satisfy myself 

 that true side lobes exist. In certain preparations the internal apparatus is unusu- 

 ally exserted, and the curious lateral blades are in a position in which they might 

 readily be taken for the side lobes of the vulvar scale. The segment, behind the 

 vulvar scale, has on either side an oval lobe beset with hairs. 



The internal apparatus is very different from all the other species examined, 

 with respect to the form of the apex of the lateral blades ; a better idea of which 

 will be gained from a reference to the figure than from a description. The central 

 triangular piece is of a form similar to that found in the two preceding species, 

 while the foot-shaped piece in the " heel " portion seems to assume a pocket-like 

 form, which is more characteristic of the two species which follow. 



A. FIMBKIATA, Pictet. 



The 9th segment is rounded on the margin when viewed from above, and the 

 tubular piece is as a rule little visible in preparations excepting as a little rounded 

 process. 



The vulvar scale is relatively strong in its middle lobe, which has sometimes a 

 slightly clavate form, but the preparations vary in this respect. The side lobes are 

 strongly defined, slightly blunt and hairy. The internal apparatus is short and 

 robust in this species ; the central triangular piece is short and broad, while the 

 foot-shaped piece has a relatively very large " heel " or pocket (the figure, however, 

 shows, I think, the maximum development in this respect). 



