410 THE COCCIDAE 



densaria of second incisura largest; pectlnae small, about five, 

 arranged 2, 0, 3; dorsal oraceratubae conspicuous; genacerores 

 (6-7)2-4. — Colorado, New Mexico on plum howardi Ckll. 



bb. Pygidium with pectinae and plates of each lateris subequal in 

 size; median pair of lobes large, quadrangular, distinct lateral 

 and mesal notches; second pair of lobes one-third or less the 

 width of median lobes, shorter, small lateral and mesal notches, 

 hyaline; small third pair of lobes sometimes present; pectinae 

 subequal in length to lobes, arranged 2, 2, 5-6, those of incisurae 

 and three cephalad of each second iobe furcapectinae, others 

 plates; genacerores 0-1(4-7)4-6; densariae not prominent, subequal. 

 — Virginia, Ohio on Epigaea. epigaeae Marl. 



aa. Pygidium never with more than three pectinae or plates on each 

 lateris. 

 b. Pygidium with plates in median incisura. 



c. Pygidium with second pair of lobes small, usually narrow, 

 longer than broad, if broader than long, never twice as broad 

 as long, 

 d. Pygidium with mesal and lateral margins of second densariae 

 subequal in length. 



e. Pygidium with median pair of lobes quadrangular, broader 

 than long, rounded, prominent lateral notches, mesal mar- 

 gins suboblique; second pair of lobes usually as broad as, 

 sometimes broader, than median, but much shorter, lateral 

 margin oblique and emarginate or irregularly notched; me- 

 dian incisura with two short plates, each second incisura 

 with two plates or finely serrate pectinae, each lateris with 

 two plates or two furcapectinae in third incisura and a 

 single unapectina; setae long, particularly those of second 

 pair of lobes; genacerores 5-8(10-12)10-16; anus five times 

 its width from caudal margin. — Aspidiotus ostreaeformis 

 oblongus Goethe, Aspidiotus ostreaeformis magnus Goethe. 

 — British Columbia, Idaho, California, Eastern Canada, 

 New York, Michigan, Europe on apple, pear, plum, peach, 

 cherry, birch, poplar, horse-chestnut, linden, alder, maple, 

 oak, date-palm, Crataegus, Calluna... -ostreaeformis Curtis. 



ee. Pygidium with the median pair of lobes projecting, more 

 or less parallel, longer than broad, distal end uniformly re- 

 duced, mesal and lateral notches; second pair of lobes very 

 small, broad with irregular margin ; genacerores always In 

 four groups, (4-11)3-9; other structures assumed to be same 

 as in ostreaeformis. — Bavaria, Prussia, Austria, Norway, 

 England, Portugal on Calluna, Erica havaricus Lindgr. 



dd. Pygidium with mesal margins of second densariae longer 

 than lateral; median pair of lobes wide, sometimes with 

 lateral notch ; second pair of lobes with prominent mesal 

 angle, distal margin oblique, one to four notches; plates 

 small, arranged 2, 2, 3; genacerores 2-6(5-12)5-7. — Aspidiotus 

 fernaldi albiventer Hunter, Aspidiotus fernaldi hesperiua 



