June, '11] 



DAVIS : ILLINOIS APHIDIDCE 



331 



Plate 10. Aphid Structures 



typical *S. pastinacce, that I collected at Vancouver some years ago, 

 is so similar to our material that the three are no doubt the same. 



Explanation of Plate 10. 



Phorodon galeopsidis Kalt. — Fig. 1, wing; 2, antenna; 3, head; 4, cornicle; 5, 

 style of winged vi\aparous female. 



Macrosiphum cratcegi Monl. — Fig. 6, antenna of wingless viviparous female. 



Macrosiphum lactucce Schr, — Fig. 7, head; 8, abdomen; 9, antenna; 10, wing of 

 winged viviparous female; 11, antenna of wingless viviparous female. 



Camera lucida drawings, figures 3, 4, 5, and 7, with one-inch eye piece and two- 

 third objective; 2, 8, and 10 with one-inch eye piece and one and a half inch objective; 

 6, 9, and 11 with a two-inch eye piece and two-tliird objective; 1 with a two-inch 

 eye piece and one and a half inch objective. 



