198 THE ENTOMOLOGIST. 



areolets. The Asilidae generally, including Laphria and 

 Dasypogon, are distinguished by the completeness of their 

 wing-structure, by their powerful flight, by their robust 

 bodies, by their thirst for blood, and by their lancet-like 

 mouths, from which the wing-case of beetles is not always 

 a sufficient defence : they chiefly abound in hot regions, 

 where they help to maintain the balance of life, by limiting 

 its excess in some forms. The radial areolet is open in 

 Dasypogon, closed in Laphria and in Asilus; in the first 

 genus the radial and subcostal bones are separate, in the 

 second and third they are united before they reach the 

 border. The resemblance between the wing of Rhyphus and 

 that of Leptis has been already remarked : in the former 

 there are two radial areolets, one cubital areolet, and the anal 

 areolet is open to the border; in the latter there are one 

 radial areolet, two cubital areolets, and the anal areolet is 

 closed before the border. 



Francis Walker. 



Occurrence of Butte rjlies at Dry Drayton, in the Months of 

 March, April, May, June, 1874. By the Rev. F. A. 

 Walker, M.A. 



1. Pieris Brassic(B.—k-^n\ 7, 23, 25, 27, 28, 29; May 17, 

 18, 21, 31; June 1, 2, 3, 4, 5, 6, 7, 21, 27. Observed on 

 nineteen different days in April, May, June. 



2. P. Bapce.—kYixW 20, 21, 22, 23, 24, 25, 26, 27, 28 ; 

 May 2, 8, 18, 21, 22, 24, 31 ; June 2, 4, 5, 6, 7, 21, 27. Ob- 

 served on twenty-three different days in April, May, June. 



3. P. Napi.—A^xW 25, 27, 28, 29; May 1, 5, 6, 17, 

 18, 29; June 5, 9. Observed on twelve different days in 

 April, May, June. 



4. Anthocharis Cardamines. — April 29; May 16, 18, 21, 

 22, 24, 26, 30, 31 ; June 2, 3, 9. Observed on twelve different 

 days in April, May, June. 



Total number of appearances of Pieridae, sixty-six. 



5. Gonepteryx Bhamni.—Male : March 18, 23, 24, 28; 

 April 3, 20, 21, 22, 27, 28; June 5(?). Observed on ten 

 diff'erent days in March and April, one in June; but my eyes 

 might have deceived me concerning this last appearance, 



