8 



Rliynchcenus proboseideus, I am still inclined to. think is 

 the prohoscideus of Fabricius, as the length of the proboscis and 

 the color of the body vary in every specimen which I have 

 observed. The proboscis of one was at least longer than the 

 body; but that method of giving the measure of insects I 

 find very incorrect in most authors, and liable to deceive 

 the student. 



Pelecinus polycerator is common among us. I have usually 

 found it on the oak trees, flying slowly, and easily caught ; 

 its turns its abdomen like a wasp, or an ichneumon, appar- 

 ently striving to sting the hand that holds it. 3Iidas filata is 

 not very rare, but caught with difficulty. 



HENTZ TO HARRIS. 



Northampton, Jan. 1, 1826. 



I have taken pains to dissect two specimens of Chremas- 

 tocheilus ; this is the result. The different parts of the mouth 

 do not materially differ in shape ; but in the smallest spe- 

 cies, 0. castmicus, I could not see any trace of the labium 

 (upper lip), whilst in 0. p>iger that part is quite large. 

 Thinkino; that I mioht have lost or left unobserved the labium 

 In the first dissection, I took another insect of the same species, 

 the last but one in my cabinet, and became convinced that that 

 part was certainly wanting in C. castaneus. I sent a draw- 

 ing of both species to Mr. Say, Avith descriptions, more than 

 three months ago, and thought my letter might not have 

 reached him ; but some days ago I received an obliging answer 

 to my various questions. He thinks both species are new, as 

 both diffc'r from the description of 0. castaneus ; that I can- 

 not decide, for all the knowledge I have of that species is de- 

 rived from a very short description by Latrcillc (in the Hist, 

 des Crust, et dcs Ins.) which describes it as being tout noir, 

 and refers to Knoch, but I have not the work of that naturalist. 



