306 THE COCCIDAE 



k. Pygidium with caudal margin convex, 

 never concave with median pair of lobes 

 located in concavity; brevaceratubae always 

 few in number. 



I. Pygidium with anus located about its 

 own width from vulva, distant from 

 caudal margin. Epidiaspis Ckll. 



II. Pygidium with anus located about mid- 

 way between vulva and caudal margin. 

 Type, Diaspis montana Ckll 



Cockerellaspis MacG. 



kk. Pygidium with caudal margin deeply con- 

 cave on meson with median pair of lobes 

 in concavity; brevaceratubae usually nu- 

 merous; anus located nearly midway be- 

 tween vulva and caudal margin than to 



vulva. Diaspis Costa. 



ii. Pygidium with truncate lobe-like projections 

 located in incisurae other than median. Type, 



Diaspis regularis Newst Umbaspis MacG. 



hh. Pygidium with median pair of lobes fused into 



single area. Type, Chionaspis malloti Ruth 



Rutherfoi'dia* MacG. 



gg. Pygidium without plates in incisurae or on lateres. 



h. Pygidium with two pairs of lobes, five groups of 



genacerores, anus located near caudal margin, and 



large altaceratubae Protargionia Leon. 



hh. Pygidium without lobes, genacerores forming 

 U-shaped group, anus located distant from caudal 

 margin, and altaceratubae small or wanting. Type, 



Protodiaspis agrifoliae Essig Essigaspis MacG. 



ff. Scale of adult female never circular, always pyriform, 

 mussel-shaped, mytilaspiform, or linear, twice or more 

 as long as wide, rarely with poorly defined scale and 

 living in gall. 



g. Insects always living exposed, never producing ab- 

 normal growths or galls upon plants, 

 h. Pygidium of adult female always with plates in 

 incisurae or on lateres. 



i. Pygidium with caudal margin convex, never 

 with deep angular or semicircular pygidial in- 

 cision. 



j. Pygidium with mesal margins of median 

 pair of lobes convexly rounded and diverg- 

 ent, if straight, two margins usually distant, 

 if straight and adjacent, proximal ends fused, 



*This genus is named for my former student, the late Andrew Rutherford, who died 

 from enteric fever while in service as Government Entomologist of Ceylon. 



