STATES OF INSECTS. 303 



mon orange-tip [Pieris Cardamines F.), one sex has not 

 the orange tip to the upper wings : and, to name no more, 

 the male of Lyccena dispar, one of our rarest and most 

 beautiful butterflies, has only a single black spot in the 

 disk of its fulgid wings ; while in the other sex, the pri- 

 mary pair have nine, and the secondary are black, with 

 a transverse orange fascia near the posterior margin. 

 But the most remarkable difference in this respect ob- 

 servable in the insects of the order in question, takes 

 place in a tribe, of which only one species is certainly 

 known to inhabit Britain — I mean the Papiliones Equites 

 of Linne : what he has called his Trojani and Achivi in 

 some instances have proved only different sexes of the 

 same species. Mr. MacLeay's rich cabinet affords a sin- 

 gular instance confirming this assertion ; — a specimen of 

 a Papilio is divided longitudinally, the right hand ^ide 

 being male, and the left hand female. The former be- 

 longs to P. Polycaon, a Grecian, the latter to P. Lao- 

 docus, a Trojan. An instance of two Grecians thus united 

 is recorded in the Encyclopedie Methodique, as exhibited 

 in a specimen preserved in the; Museum of Natural Hi- 

 story at Paris; which on the right hand side is P. Ulysses, 

 on the left P. Diomedes a . 



In the Neuroptera, the Libellulidce are remarkable for 

 the differences of colour in the sexes. In the common 

 Libellula depressa, which you may see hawking over 

 every pool, the abdomen of the male is usually slate- 

 colour, while that of his partner is yellow, but with darker 

 side-spots. Reaumur, however, noticed some males that 

 were of the same colour with the females b . Schelver 



a ix. 65. n. 110. h vi. 423. 



