1870.] 55 LMinot. 



the types of Kirby, described in the Fauna Boreali Americana, 

 as well as in his MonogTaphia Apum AngliaB, are still in ex- 

 istence, in the British Museum. 



The following paper was read : — 

 Notes on the Flight of N. E. Butterflies. By Charles 



S. MlNOT. 



In the course of the past summer I spent a good deal of time 

 investigating the flight and some of the habits of the imagines of our 

 common New England butterflies. Though my studies on this sub- 

 ject are far from complete, yet a few remarks may not be uninter- 

 esting. 



My experiments and observations have not as yet extended to 

 the mechanical principles, but merely to the character, of the 

 flight, and the influence of certain structural differences upon it. 

 I find that, according to their flight, the New England butterflies 

 may be divided into three large divisions, each of which may be 

 again divided into two or three sections, which may be further di- 

 vided into groups, each of which will contain usually a single genus 

 and all the species of that genus. I give an example quoting the 

 three main divisions. 



I. Flight sweeping, long, sailing. 

 A. Not turning often. 



a. Strong and steady. 



1. Prolonged, swift. Papilio. 



IT. Flight not sailing, shorter than in I, more or less undulating. 



III. Flight jerky, generally short. 



The terms which I have used above will be understood only by 

 those who have watched the butterflies out of doors. There is 

 another division, more artificial but equally possible, which has no 

 immediate connection with the flight, which I give below. 



Genera, the individuals of which, if disturbed, return after a short 

 interval to the same spot. 



I. Usually; as T^hecla, Grapta, Hesperia, etc. 



II. Seldom ; as Melitsea, Pieris, etc. 



I will speak only of one or two of the other facts that I have noticed. 

 A large thorax which allows room for powerful muscles, with a stiff 

 crust, which gives a firm point from which the muscles can act, 



