427 



from the upper, and a current of air would rush through between 

 the wings, and compel the butterfly to employ additional force to 

 keep them together ; as thus arranged, the resistance of the air 

 keeps the Avings together during the downward beat, and their 

 elasticity during the upward. The curve in which any point of 

 the wing moves during one beat is an arc of a hehx, and not an 

 arc of an ellipse as Strauss-Durckheim supposes. 



The Corresponding Secretary read a letter from Dr. I. 

 I. Hayes, acknowledging the receipt of notice of the So- 

 ciety's action with reference to his proposed Arctic expe- 

 dition, and requesting permission to publish the Report 

 of the committee. It was voted that he be permitted to 

 make such use of the Report as he may think for his 

 advantage. 



The Corresponding Secretary also read the following 

 letters which he had recently received, viz : — 



From the Smithsonian Institution, February 20 and May 19, 

 1858, acknowledging the receipt of publications of this Society ; 

 from the Real Academia de Ciencias de Madrid, August 1, 1857, 

 presenting its Memoirs, 3d Series, tomo 2% parte 2^^ ; Wilham 

 Sharswood, Philadelphia, Nov. 11, concerning the proposed pub- 

 lication of the descriptions of certain insects, «&;c. ; M. Auguste 

 Le Jolis, Cherbourg, France, Nov. 15, 1858, in acknowledgment 

 of his election as Corresponding Member ; Stephen P. Leeds, 

 Rutherfordton, N. C, Oct. 28, and William G. Binney, Burling- 

 ton, N. J., Nov. 17, also acknowledging their election. 



The committee to whom was referred the nomination 

 of a candidate for Curator of Comparative Anatomy, 

 reported the name of Dr. James C. White, of Boston — 

 and he was chosen. 



A vote of thanks was passed to Mr. Daniel F. Hicks, 

 of Wabashaw, Minn., for the donation of a sharp-tailed 

 grouse, Tctrao ])hasianeUus, Linn. 



Hon. Richard Hill, of Kingston, Jamaica, was chosen 

 a Corresponding Member; and Mr. Nathan Farrand, of 

 Boston, a Resident Member. 



