SUBFAMILY DIASPIDINAE 235 



since they occur in widely separated groups. 



There is located in the cephalic region of the dorsal aspect 

 of the pygidium of certain species a curved transverse band of 

 thickenings which were named by Leonardi the calli and here 

 designated as the calles. They are the transverse thickenings of 

 Marlatt and the basal thickenings of Dietz and Morrison. The 

 calles exist in four conditions. There may be four distinct sepa- 

 rate thickenings, two on each side of the meson, the one on each 

 side adjacent to the meson is known as a mesal callis and the 

 one laterad of each mesal callis as a lateral callis; there may be 

 a transverse band of three thickenings, the mesal one much long- 

 er than either of the lateral and evidently formed by a fusion of 

 the mesal calles; there may be a transverse band of two thicken- 

 ings, one on each side of the meson, each evidently formed by a 

 fusion of the mesal and lateral calles of a side; or there may be 

 a single transverse thickening, evidently formed by a fusion of 

 the two mesal and two lateral calles. 



In certain species there are thickenings which appear to be 

 proximal prolongations of the lobes. These thickenings extend 

 through the cuticle and for some distance beyond the proximal 

 ends of the lobes. They are characteristic in form for certain 

 species and only of certain individuals of other species. They 

 seem to vary considerable in extent and appearance depending 

 upon the amount of treatment given the specimen with caustic 

 potash. They are designated as anomaladensae to distinguish 

 them from the other thickenings of the pygidium. They are in- 

 correctly designated as ventral thickenings by some writers. 



On the ventral aspect of the pygidium of many species, there 

 are more or less distinct thickenings that are similar in general 

 appearance to the calles, but they are situated on the ventral 

 aspect and extend longitudinally instead of transversely. They 

 may be known as the paradensae and in common with some of 

 the other thickenings of the pygidium have been previously called 

 ventral thickenings. The paradensae are located laterad of the 

 vulva, but vary somewhat in position. They are more frequently 

 located on the mesal than on the lateral side of the genacerores. 

 In some species they are located mesad of the postgenacerores 

 and laterad of the pregenacerores. In such cases there are two 

 portions which may be connected by an oblique thickening or the 

 connection may be wanting. If necessary to distinguish these 

 two portions of each side, the cephalic portion may be known as 

 a preparadensa and the caudal as a postparadensa. The portion 



