TRIBE DIASPIDINI 325 



broad, broader than long, entire, distant; third pair of lobes tri- 

 angular, almost obsolete, lateral margin long, oblique, entire; 

 plates longer than lobes, arranged 0, 2, 3, 11, those of each lateris 

 arranged (2-2-2) -4-1; setae small; dorsal oraceratubae arranged in 

 three broad uninterrupted bands; latadentes in second and third 

 incisurae; genacerores 16-19(17-33)13-29. Algeria on Nerium, 



Oleander. nerii Newst. 



bb. Pygidium with second pair of lobes incised, mesal lobelet elongate, 

 broadly bluntly rounded, one-half width of median lobe, lateral 

 lobelet shorter and narrower than mesal; median pair of lobes 

 adjacent at proximal end, divergent caudad, longer than broad, 

 distal end bluntly rounded; third pair of lobes not incised, simi- 

 lar in form to mesal lobelet of second pair; plates about as long 

 as or shorter than median pair of lobes, arranged 0, 2, 2, 8-9, 

 those of each lateris arranged 2-2-4to5; anus located between pre- 

 genacerores; each lateris with seven altaceratubae; dorsal ora- 

 ceratubae small, arranged in rows; genacerores 12-13(20-29)18-22. 



China on Populus. micropori Marl. 



aa. Pygidium with both second and third pairs of lobes incised. 



b. Pygidium with two plates in each second incisura, only rarely 

 with one, if so, each lateris with plates arranged in two groups. 

 c. Pygidium with genacerores arranged 15-20(30-40)25-30; median 

 pair of lobes triangular, pointed, not adjacent, divergent, en- 

 tire; second pair of lobes large, smaller than median, incised, 

 mesal lobelet larger than lateral, bluntly rounded; third pair 

 of lobes small, rudimentary; plates twice as long as median 

 pair of lobes, mesal plate of each group shortest, arranged 

 0, 2, 2, 6, those of each lateris arranged 2-2-2; submarginal 

 setae distinct, marginal setae prominent; anus and vulva su- 

 perimposed, seven times its width from caudal margin. Massa- 

 chusetts, California on Spartina spartinae Comst. 



cc. Pygidium with genacerores always much less in number than 



15-20(30-40)25-30. 



d. Pygidium with median pair of lobes finely serrate, large, 

 longer than broad, bluntly pointed, proximal ends adjacent, 

 divergent caudad; second and third pairs of lobes incised, 

 mesal lobelet largest, distal ends bluntly rounded and 

 toothed; latadentes in second and third incisurae; plates 

 slender, longer than median pair of lobes, not twice as long, 

 arranged 0, 2, 2, 8-9, those of each lateris arranged 2-2or3-4; 

 caudal preabdominal segment with four or five plates on 

 each side; anus located distinctly cephalad of vulva; gena- 

 cerores 4-6(5-8)2-7. New York, Virginia, Georgia, Ohio, Eng- 

 land, France on Euonymus euonymi Comst. 



- dd. Pygidium with median pair of lobes entire, divergent, dis- 

 tance between them nearly equal to width of median lobe, 

 broadly rounded; second pair of lobes incised, lobelets 

 large, mesal larger than lateral, slightly longer than broad, 

 entire, broadly rounded; third pair of lobes incised, lobelets 

 subequal in width, mesal larger than lateral, distinctly long- 



