100 ILLINOIS BIOLOGICAL MONOGRAPHS [342 



EXPLANATION OF PLATE VII 



SPINNERET 



39. Lycopliotia margaritosa, last instar, cephalic aspect of spinneret. 



40. Agrotis ypsilon, first instar, distal portion of labium, caudal aspect. 



41. Agrotis ypsilon, second instar, caudal aspect of spinneret. 



42. Agrotis ypsilon, second instar, cephalic aspect of spinneret. 



43. Agrotis ypsilon, third instar, distal portion of labium, caudal aspect. 



44. Agrotis ypsilon, last instar, distal portion of labium, caudal aspect. 



45. Agrotis ypsilon, last instar, lateral aspect of spinneret. 



46. Agrotis ypsilon, last instar, cephalic aspect of spinneret. 



kxs hjpopharyngeal setae sis pro-Kimal sclerite of spinneret 



Ip labial palpus siu upper lip of spinneret 



pp palpiger siw lower lip of spinneret 



si spinneret sp stipulae 



sif fringe of spinneret spr sensoria of palpiger 



sio proximal fold of spinneret sps stipular setae 



sir rudimentary fringe of spinneret sr sensorium 



