Merodon may be distinguished from the extensive genus 

 Syrphus by the regular form of the profile and the sinuated 

 nerve in the wings ; from Tropidia Meig., which it most re- 

 sembles, both in its dentated thighs and the lobed cell of the 

 wings, it is separated principally by the form of the 3rd joint 

 of the antennae ; the clypeus is more produced in that genus, 

 and the species are not so woolly as in Merodon : the same 

 differences, as well as the simple legs of the Helophili, at once 

 separate it from that genus ; and the plumose antennae of Eri- 

 stalis render it difficult to confound it with them. 



The genus Merodon must be far from common in this 

 country, since we have only discovered one species at present 

 out of 27 described by Meigen; and only 2 specimens of that, 

 both of which are males, taken by Dr. Leach in Spitchwick 

 park, Devon. Never having seen the other sex, I have been 

 compelled to transcribe Meigen's description of it. The few 

 indigenous Liliaceous plants we have in this country may be the 

 cause of our not having at present detected any more speci- 

 mens, for it is well known that our genus is attached to the 

 Narcissi, from which cause one has received its specific name ; 

 and Reaumur {v. 4. p. 572.) has given figures of the larvae, 

 &c. of a species that feeds upon the roots of those plants. It 

 would therefore be worth while to examine meadows where 

 the Narcissi grow spontaneously, when they are in flower ; for 

 if one of the flies were found in the neighbourhood, there 

 would be good reason to suppose they were bred there : and 

 in November the bulbs ought to be examined for the larvae, 

 which in all probability are easily reared ; and additional in- 

 formation respecting the oeconomy of a genus whose habits are 

 so peculiar, would be highly interesting to the Entomologist, 

 and probably beneficial to the Florist. 



The specimen of Narcissus, Pscudo narcissus (Common daf- 

 fodil), I received from Professor Henslow, who gathered it 

 the beginning of April near Cambridge ; Mr. Dale also showed 

 me numerous specimens soon after, growing at Glanville's 

 Wootton, that were evidently wild. 



