BRITISH BUTTERFLIES. 



and the next following is still more so ; the 

 rest gradually decrease in distinctness, until 

 almost obliterated towards the apex ; they 

 consist of a dark centre and pale circumscrip- 

 tion. Above, and parallel with this series, 

 twere is frequently a very fnint series of pale 

 Hoots, some times of a crescentic form; but in 

 nanny specimens these are scarcely discernible. 

 Tbe under side is dark brownish gray, with 

 numerous transverse ashy gray markings, a 

 series of which, in the form of crescents, runs 

 parallel with the hind margin of all the wings; 

 and on the hind wings this pale colour often 

 assumes the form of a transverse bar between 

 the hind margin and the middle of the wing. 

 At the anal angle of the hind wing are two 

 compound spots, which are black in the centre, 

 and orange above, and their lower border is 

 decorated with brilliant metallic gr>'en. Con- 

 tinuous with a wing-ray which passes between 

 those two spots is the long slender tail already 

 described. 



LIFE HISTORY. The last-disclosed females 

 of this species lay their EGGS on the twigs 

 of the bladder senna (Golutea arboresc.ens), but 

 like those of several, and perhaps all, the 

 British species of this family, they do not 

 hatch until the following summer, at which 

 season the young pods of the senna are 

 sufficiently advanced to serve as the food 

 of the young CATERPILLAR, which at first is 

 almost black, and then feeds on the scarcely- 

 formed pods ; subsequently, it enters the pods 

 through a nearly circular aperture, and de- 

 vours the seeds ; before attaining its full size 

 it migrates frequently from pod to pod, only 

 devouring the seed in the interior : it rests on 

 the pods or on the twigs in a straight position, 

 its shape scarcely allowing of any other. The 

 Lead is very small, scarcely half so wide as 

 tbe second segment, into which it is sus- 

 ceptible of being with drawn, and thus entirely 

 concealed : the body is shaped like a wo. id- 

 louse, the dorsal area convex, the ventral area 

 Hat, and the incisions of the segments are very 

 clearly marked. The colour of the head is 

 black : the dorsal area of the body olive- 

 green, reddish brown, or bright green ; there 

 j*. a dark, moderately wide, and periediy 



continuous medio-dorsal stripe, extending 

 from immediately behind the head to the anal 

 extremity, and also a white lateral stripe below 

 the spiracles, which are yellow ; immediately 

 above each spiracle, with the exception of the 

 first and last, there originates a rather short 

 line, which passes obliquely forwards and 

 upwards towards the medio-dorsal stripe, but 

 never unites with it ; these oblique lines are 

 longitudinally double throughout, the upper 

 part being darker, and the lower paler than 

 the groundcolour; the claspers are concolor- 

 ous with the ventral area ; the legs are brown. 

 When full fed this caterpillar never remains 

 within the bladder on the seeds of which it 

 has fed, but (generally in the month of Sep- 

 tember) it escapes from the pod which had 

 last served as its dwelling-place, and either 

 descends among the dried leaves or attaches 

 itself to a branch of the shrub, and in five or 

 six days assumes the chrysalis state. The 

 CHRYSALIS is attached by a belt round the 

 middle to the stem of the food-plant ; it is 

 obese, and rounded at both extremities ; its 

 colour is testaceous yellow or dull red, adorned 

 with brown dots, which are particularly 

 numerous about the crown of the head; there 

 is also a continuous dark line in front, extend- 

 ing from the thorax to the anal segment; the 

 spiracles are black, and plainly discernible 

 with the naked eye. The caterpillar is in- 

 fested by a minute ichneumon (Microgaster 

 glomeratus), fourteen or fifteen of which fre- 

 quently feed on a single caterpillar, and these, 

 escaping through the skin of the butterfly- 

 caterpillar, spin a cluster of little yellow 

 cocoons, attaching them to the stalks or leaves 

 of the food-plant Milliere. 



Obs. I have extracted the foregoing par- 

 ticulars from M. Milliere's beautiful work, 

 kindly lc:u me by Mr. Doubleday, from whom 

 I obtain the additional information that the 

 caterpillar is also found feeding in the pods of 

 the field pea. 



TIME OF APPEARANCE. In France this but- 

 terfly emerges from the chrysalis in Septem- 

 ber, and continues to fly throughout October. 

 In this country it may occur in our pea helds 

 now and then, but its existence must oe very 



