TRIBE ASPIDIOTINI 



413 



tinct lateral notch, distal margin bluntly rounded; anus two 

 to two and one-half times its width from caudal margin; 

 pectinae small, furcapectinae, arranged 0, 4, those of each 

 lateris arranged 2-2-0; dorsal oraceratubae arranged in lon- 

 gitudinal rows; genacerores 0-3(15-23)6-14. Ohio on Lirio- 

 dendron. piceus Sands. 



dd. Pygidium with three pairs of densariae, mesal thickening of 

 densariae of second and third incisurae much broader and 

 longer than the lateral, those of second incisura much larger 

 than those of third; median pair of lobes large, quadrangu- 

 lar, convergent, distinct lateral notch, distal margin rounded; 

 anus twice its width from caudal margin; each second in- 

 cisura with two long furcapectinae and each third with three 



long plates; genacerores (11-15)7-10. Texas on Morus 



mori Herrick. 



bb. Pygidium without pectinae on each lateris, but with plates or at 

 most with a single pectina. 



c. Pygidium with two or three pairs of densariae. 



d. Pygidium with densariae in median incisura; median pair of 

 lobes subquadrangular, longer than broad, distal end rounded, 

 lateral notch only; densariae of median incisura ovate in out- 

 line, those of second and third incisurae subequal, those of 

 third incisura smaller than those of second; genacerores 



0-2(5-7)3-4. Kansas, Iowa, Georgia on Quercus, Ostrya 



osborni Newl. & Ckll. 

 dd. Pygidium never with densariae in median incisura. 



e. Pygidium with two pairs of densariae, those of mesal side 

 of second incisurae terminating in distinct oval knob, 

 longer than those of lateral side, those of second incisura 

 smaller, mesal side longer than lateral; median pair of 

 lobes quadrangular, two lateral notches, minute mesal 

 notch, sometimes wanting; anus minute, in line with mesal 

 densariae of second incisurae; plates inconspicuous; mesal 

 calles fused, sometimes separate, distant from oblique lat- 

 eral calles; genacerores (1-3)0-1. Mexico on Coursetia 



coursetiae Marl. 



ee. Pygidium with two pairs of densariae, those of second and 

 third incisurae subequal in size, none of them swollen, 

 f. Pygidium with median pair of lobes twice as long as 

 width of anus, anus five times its width from caudal 

 margin and about ten times from vulva; median pair of 

 lobes large, prominent, bluntly rounded, distinct later- 

 al notch, mesal margins divergent; plates short, not as 

 long as median pair of lobes, arranged 0, 3-4, two in 

 each second incisura and one or two in third, these 

 sometimes lacinate; mesal calles fused, lateral calles 

 distinct, distant from mesal; genacerores 2-2(5-9)3-7. 



California on Abies, Libocedrus, Pseudotsuga 



ehrhorni Colm. 



