THE COMMON B UTTERFLIES OF THE PLAINS OF INDIA. 781 



the position of these threads being over segment 4 or 5 as is usual 

 for all butterflies. The period of absolute quiescence at this stage 

 varies, sometimes amounting to some days in normal cases. Then the 

 outward change commences. The larva begins to heave and squirm, 

 the skin splits down the three thoracic segments 2-4 at the 

 last gigantic effort, the head divides down the middle and along the 

 sides of the clypeus and the pupa begins to emerge slowly and with 

 e\'ident difficulty. The thoracic portion first disengages itself, the 

 tracheae of the spiracles appearing as thin, white threads which are 

 left behind, evidently everted ; then the head ; then, by slow degrees 

 and gradual backward and forward movements of the whole abdomen 

 in successions of waves, the skin is pushed back until it reaches the 

 very end when the cremaster is heaved out and curled over the skin 

 lump accumulated under it, and pressed into the pad of silk above 

 mentioned ; then a series of screwing squirms, to entangle the little 

 hooklets with which the extremity is provided, completes the oper- 

 ation. The pupa is held in position against the discarded skin by 

 the end of the extensor ridges which form the lateral, ventral edges 

 of the cremaster, the skin itself is held fixed to the pad by the anal 

 claspers. The final screwing wriggle is generally sufficient to eject 

 the lump of skin from its hold on the pad, sometimes it remains where 

 it is. When freshly emerged, the pupa is as long as the caterpillar 

 was but very soon consolidates itself and becomes shorter and hard. 

 All external parts of the future butterfly, although intimately soldered 

 together, can now be distinguished clearly, even to the veins in the 

 upper wings — the lower being covered by these ; the hind legs are 

 also covered. The period of the pupal stage varies, being generally 

 longer the greater the bulk. At an average estimate it lasts ten 

 days ; sometimes being as short as seven. 



The process of emergence of the pupa is the same generally 

 throughout the Lepidojjtera ; so there is nothing characteristic of 

 this family in that. When we come to distinguishing characteristics 

 of the pupa itself, it is somewhat difficult. Perhaps the chief one 

 is to be found in the cremaster. In most moths the hooklets at the end 

 when present (in some they are practically non-existent) are arranged 

 in a definite order and are, mostly, eight in number. In all butter- 

 flies, and therefore, also, in the skippers, they are, on the contrary, 

 not so arranged and their number is large ; they seem to be bunched 

 together in groups or lines or in one group or one line without any 

 order. In most moths, as a matter of fact, there does not seem to 

 be any defined cremaster, the goemeters forming one exception to 

 the rule. The head, the thoracic segments, the abdominal segments 

 barring the cremastral one, offer no character for distinction. Neither 

 do the antennae, palpi or legs. The proboscis is, generally, in the 

 same case although, in a few instances, it is prolonged free beyond 

 the ends of the wings — not that this feature would help to distinguish 



