14 BUTTER.FLIES OF THE RIVIERA 



Cannes, &c.; and at Saint-Martin-Vesubie it is taken 

 as high as the Cascade of the Boreon. 



OVUM. The ova are long, thickest in the centre 

 and tapering to a point at each end, and, like all of 

 the genus, ribbed longitudinally with grooves ; they 

 are shiny. When extruded, their colour is pale 

 greenish-blue, which soon changes to deep orange 

 inclining to red, and, before the exit of the young 

 caterpillar, to lead colour, darkest at the apex. They 

 are laid singly, attached by the base whichis flattened, 

 in an erect position on the buds or the stems of the 

 buds of Biscutella, &c., there being sometimes as 

 many as six or seven eggs on one plant. 



They are found in April. 



On April 19 th this year, I collected twenty-six ova 

 of the present species, together with larvae. Two only, 

 out of this quantity of eggs were bluish in colour. 



The next day, several of them changed to a dark hue. 



LARVA. On Biscutella didyma, B. Burseri and 

 other Cruciferae, from April to the end of June. 

 I have met with very small caterpillars, as early as 

 April 19 th , in two different seasons (1890 and 1892), 

 and as late as June 18 th . 



PUPA. In May and of June. Those of the summer 

 brood are capable of remaining as chrysalids for a 

 period of two and even three years. 



VARIETIES. v. Ausonia. 

 and v. Simplonia. 



The former of these is a variety of the second 

 brood, and is found in the same localities as the type. 



Simpolonia corresponds to the ab. Bryoniae of 

 P. Napi. 



