199 



domen fulvous, with a dorsal and ventral black vitta, widely 

 interrupted by the sutures. 



You observe here some differences, particularly in tlie color 

 of the abdomen of the female, yours being described as tawny- 

 red ; Fitch and Say's as black above, etc. 



Miss Morris describes the female of her species as quite 

 black, or blackish-brown, and not like Say's female. The male, 

 on the contrary, she states to agree with Say's description in 

 every particular. I hope you will give me a description of the 

 species which you recognized as similar to Miss Morris' speci- 

 mens, unless you can succeed in obtaining living specimens. 



HEKB.ICK TO HARRIS. 



New Haven, May 30, 1848. 



Dm-ing the first year of my entomological studies I gradually 

 came to the conclusion that the number of joints in the antennas 

 of' the Hessian Fly, and also of several others of our Cecido- 

 myicB could not be depended upon for constancy ; and ultimately 

 I made it a rule, whenever I met with a Hessian Fly, at once 

 to set down the number of the joints in the antennae. Many of 

 these data I must have consulted when I wrote the paper in the 

 Patent Office Report issued in 1845. Special attention was 

 given to those cases where I saw the insect in the act of evolu- 

 tion from its thin membranous exuvia, for I thought it probable 

 that many of those found in the field had suffered some muti- 

 lation in the antenno3. 



I copy now from almost the first paper which meets my eye. 



"May 13, 1833. O. destructor^ male, evolved this morning; 

 I saw him before more than half was extricated from the mem- 

 branous bag which envelops him. When first evolved the 

 color is much paler than a few hours after ; his thorax Avas red, 

 his genital organs quite distinct, antennas 17-jointed, besides the 



