LIFE-HISTORY OF LYCjENA ACIS. 165 



pupated ten a.m. on the 19th, the last stage occupying fifteen 

 days. 



After fifth and last moult fully grown, about two hundred and 

 seventy-five days old, it measures ^^ in. long. In shape and 

 size it greatly resembles L. arion larva. The small shining black 

 head is set on a moderately long retractile neck, which is fre- 

 quently protruded beyond the first segment while it is crawling 

 and feeding, which, when at rest, is completely withdrawn and 

 hidden in the segment. Although the head is disproportionately 

 small for the size of the larva, it is more than twice the size of 

 the minute head of L. arion larva. 



Dorsal view : The anterior and posterior segments are over- 

 lapping and rounded ; the body narrowest anteriorly, widening 

 to the eighth segment. The segmental divisions are deeply cut, 

 each segment boldly convexed. Side view : First anterior and 

 last three posterior segments flattened and projecting laterally ; 

 second to ninth segments are humped dorsally ; a slight medio- 

 dorsal furrow ; the sides sloping and lateral ridge dilated, ventral 

 surface bulbous and ample. The whole body is rather densely 

 sprinkled with finely serrated spinous hairs ; the longest are 

 along the dorsal surface and lateral ridge, where they form 

 a projecting fringe all round the larva, and the first two seg- 

 ments are also covered with longish hairs, and a few are scattered 

 along the subdorsal region ; all these longer hairs are pale 

 brownish, becoming whitish towards the base, which is in the 

 form of a pedestal, and of a greenish white colour ; the other 

 hairs are very minute, white, and glassy. On the first segment 

 is a fan-shaped whitish dorsal disc, studded with shining black 

 raised processes and tiny white hairs ; scattered over the body 

 are shining black spiracular-like discs, very small, common to 

 the Lycaenidse larvfe. On the tenth segment is a transverse 

 gland, very like that on the same segment of nrion larva, but in 

 acis it is not fringed with the extremely minute branching hairs, 

 but is instead surrounded by numerous little circular discs and 

 tiny white simple hairs ; and on each side of the eleventh seg- 

 ment is a retractile whitish tubercle ; the claspers and ventral 

 surface are glaucous ; the legs whitish, ringed with dark olive. 



The larva which entirely fed on furze- blossoms since hyber- 

 nation pupated on May 22nd, and produced a fine male imago 

 on June 7th. This larva remained a much paler colour, being 

 a pale greenish yellow-ochreous, and the pupa was likewise pale 

 in colour. 



The larvae spun themselves up on different parts of the 

 plants, both on the stems, leaves, and flowers ; in each case a 

 very slight cocoon was formed by a few strands of silk, and also 

 attached by the hind claspers to a pad of silk and a cincture 

 round the middle. 



The pupa averages in length ^^ ^^' 



