308 THE COCC1DAE 



nn. Body with head and thorax not ab- 

 normal in length, together only 

 slightly longer than abdomen. 



Type, Chionaspis minuta Green 



Tenuiaspls MacG. 



11. Pygidium with oraceratubae of breva- 

 ceratubae arranged promiscuously, nev- 

 er in crescentic transverse rows. Type, 



Chionaspis acuminata Green 



Unaspis MacG. 



kk. Pygidium with median pair of lobes minute 

 and plate-like, second pair of lobes large 

 and apparently with six plates between 



them. Type, Chionaspis striata Newst 



Lineaspis MacG. 



jj. Pygidium with mesal margins of median pair 

 of lobes straight and adjacent, rarely if ever 

 fused, two lobes together always forming 



single compact semicircular area 



HemicMonaspis Ckll. 



. Pygidium with caudal margin deeply concave, 

 forming deep angular or semicircular pygidial 

 incision, 

 j. Pygidium with median pair of lobes located 



within pygidial incision. 



k. Body with preabdomen symmetrical, dextral 

 and sinistral margins of segments similar, if 

 bearing setae on spine-like projections, 

 these confined to thorax and located on both 

 sides. 



I. Body with thorax at most never twice 

 as long as wide, varying from as wide 

 as long to one and one-half times as long 

 as wide. 



m. Thorax normal, not bearing one or 

 two small tubercle-like bracteae with 

 ceratubae on mesothorax and meta- 

 thorax, mesospiracerores usually pres- 

 ent. Phenacaspis Ckll. 



mm. Thorax bearing one or two small con- 

 ical tubercle-like bracteae with cerat- 

 ubae on mescthorax and metathorax; 

 mesospiracerores wanting. Type, Chi- 

 onaspis arundinariae Green : 



Canaspis MacG. 



II. Body with thorax with parallel sides and 

 two and one-half times as long as wide. 

 Type, Chionaspis praelonga Newst 



Cooleyaspis MacG. 



