384 THE COCCIDAE 



are of common occurrence in a number of species but only rarely 

 do they have more than two projections or pectinations and these 

 are usually distal. Some species, however, show an intergrading 

 between the reduced unapectinae and the furcapectinae. A single 

 individual may show bifurcate furcapectinae in the median incisura, 

 furcapectinae with three or four distal projections in the second in- 

 cisura, furcapectinae with three or four distal projections or those 

 with five or six distal projections in third incisura, unapectinae in 

 the fourth incisura, and broad mutipectinate unapectinae upon 

 each lateris. The plates are usually long and slender. The occurrence 

 of plates and furcapectinae upon the same individual is not un- 

 usual, the plates being confined to the median or the median and 

 second incisurae while the second and cephalic incisurae may 

 contain comparatively simple unapectinae as well as furcapectinae. 

 The simpler forms of pectinae, those with a small number of pec- 

 tinations, are found upon the caudal portion of the pygidium and 

 those with a considerable number on the cephalic portion. The 

 pygidial fringe in certain species is so reduced that not only lobes 

 but pectinae and plates are also wanting. The pectinae and plates 

 may both be wanting even when the lobes are present. The plates 

 of the median incisura are often greatly reduced in diameter and 

 length so that it is sometimes difficult to differentiate them from 

 the setae, which seem in such cases to be larger, but only rarely are 

 the plates or pectinae wanting. The plates and pectinae are quite 

 typical in their arrangement, usually as follows, 2, 2, 3 or 2, 3 or 

 2, to several. The greatest variation is found upon the lateres 

 which lack them, bear only a few, or bear one or more groups con- 

 sisting of several. 



A characteristic feature of each lateris in the pygidia of many 

 lepidosaphids and diaspidids is the presence of distinct indenta- 

 tions which are usually limited by more or less prominent projec- 

 tions, latadentes. These indentations are believed to mark upon 

 the margin of the pygidium the divisions between the segments. 

 There are usually one or two plates located on all or several of 

 these areas of the lateres in these tribes. In the aspidiotids not 

 only the indentations and projections are wanting but there is 

 no indication of a segmental arrangement of the pectinae or plates 

 when they occur upon the lateres. It may be found, when they 

 are more carefully studied, that the location of the dorsal and 

 ventral setae, which are associated with the dorsal and ventral 

 surfaces of the lobes and latadentes in the other tribes, although 

 not always located upon their respective lobes, will indicate some- 



