CORRESPONDENCE. 



HERRICK TO HARRIS. 



NEW HAVEN, Jan. 24, 1840. 



You ask me to point out the errors in Mr. Say's account of 

 Cecidomyia destructor, referring doubtless to that contained in 

 the first volume of the Journal of the Academy of Natural Sci- 

 ences of Philadelphia. These I must mention entirely from mem- 

 ory, as I cannot now go into a minute comparison of his paper 

 with my notes ; however, I feel quite confident that what I say 

 will not be erroneous. The matter Avas always exceedingly 

 interesting to me, and my memory on the subject is very clear. 



With the description (p. 45 of Vol. I, supra) I have little 

 fault to find, except that it might be much improved by a new 

 casting over. P. 46, line 1 : " thighs furnished at the tip with 

 several very acute claws " is most probably incorrect, as I have 

 searched for them in vain. As regards the importation of the 

 Hessian Fly, I am decidedly of the opinion that it was im- 

 ported, and probably from Europe, and that it is not a native 

 of this country. I have not time to go into the evidence 

 here. 



As to its being absolutely unknown in Europe, strange as it 

 is, I am inclined to think that it is unknown to their entomolo- 

 gists, as existing there ; but I have certain proof that the ani- 



