SUBFAMILY DIASPIDINAE 233 



in this respect from the densariae which are confined to the ven- 

 tral aspect of the pygidium and are never present, so far as ob- 

 served, in those species provided with paraphyses. These two 

 very different structures are confused by Leonardi and Marlatt 

 under the single name of paraphyses. The paraphyses are con- 

 tinuous, at least for the most part, with the proximal prolonga- 

 tions of the lobes while the densariae are always located between 

 the lobes. The number of paraphyses associated with each lobe 

 varies, one to three are the usual numbers, but there may be 

 more than three and some of the lobes may lack them, if want- 

 ing, it is usually from the mesal lobes. There is frequently a 

 considerable number present in a single pygidium, as many as 

 twenty-eight or fourteen pairs in some. 



The anus in the Diaspidinae is the prominent opening located 

 on the meson of the dorsal aspect, frequently near the middle of 

 its length and usually some distance from the caudal end of the 

 pygidium. It is normally located in the caudal abdominal seg- 

 ment, but the depression of this part of the body, the close apposi- 

 tion of the dorsal and ventral aspects, and the consequent reduc- 

 tion in the lumen between these areas, the anus has migrated 

 cephalad and is found in the cephalic portion of the pygidium of 

 certain species. The anus is also known as the anal opening or 

 anal aperture. 



The external opening of the female reproductive organs, the 

 vulva, is apparently constant in position in the Diaspidinae. It 

 is situated on the ventral aspect of the pygidium in the region 

 of what is believed to be the sixth segment. The position of the 

 vulva is often difficult to determine, but is generally more easily 

 identified because of the structures associated with it, the gena- 

 cerores, when these are present, and the fine radiating ridges in 

 the surface of the cuticle. The vulva is also known as the vagi- 

 nal opening, genital aperture, genital orifice, aperture sessuale 

 feminae, or genital otvor. 



Figures of pygidia usually show the position of the anus and 

 vulva as if they were both on the same aspect. The comparative 

 position of the anus and vulva, their distance from each other 

 and from the caudal margin of the pygidium, is of considerable 

 value, but the fact that they are situated on different aspects 

 must not be overlooked. The variation in position between the 

 anus and vulva is due wholly or for the most part to the differ- 

 ence in position of the anus. In the Parlatoriini the anus is 



