22 BUTTERFLIES OF THE RIVIERA 



HABITAT. Common everywhere ; rare at Saint- 

 Martin- Vesubic. 



OVUM. From May to June. 



The eggs are laid on the under surface of the 

 terminal shoots of the food-plant, and the larva 

 emerges within a week from the time of having been 

 deposited. 



Out of a large number of ova (more than twenty), 

 nearly all yielded caterpillars which fed up rapidly. 



LARVA. On Rhamnus alpinus and other species of 

 Buckthorn, in May and June. The sole caterpillar 

 which I reserved out of the above number, took 

 exactly four weeks and a day (May 19 th to June 16 th ), 

 from the time it was hatched till the date when the 

 larva changed to a chrysalis. 



It remained in the pupal state three weeks June 

 16 th to July 6 th at the end of which period one 

 evening at 7-30, the imago came forth. The time thus 

 occupied, from the birth of the caterpillar to the 

 exit of the butterfly being seven weeks and one day. 



PUPA. Is found in July. 



The chrysalid which I have in my collection is 

 fastened to a twig of the plant on which the larva had 

 formerly subsisted. 



OBSERVATION. Many entomologists consider this 

 to be a variety of the last ; but it is difficult to see 

 on what grounds. 



