430 BRITISH LEPIDOPTERA. 



Teratological specimens. — Waller records a specimen which 

 emerged from pupa with one antenna (Ent., xxiii., p. 326). 



Egglaying. —The eggs are laid singly on both sides of willow 

 leaves or on twigs, most frequently, however, on the underside, very 

 rarely on the upperside, of the leaves (Tutt) ; more usually on the under- 

 side of the leaves of the foodplant, either singly or in pairs, more rarely 

 they are laid on the smaller twigs and leafstalks (Hellins). A 2 en- 

 closed in a large muslin bag in which was a large leafy sallow branch, 

 commenced to oviposit about 8.15 p.m. of May 25th, 1898. She flew 

 noisily, stopping frequently to deposit an egg on a leaf. In about 35 

 minutes she rested against a branch and became still. The following 

 evening she repeated the business, and did so for six consecutive days. 

 I carefully counted the eggs laid each day, with the following result : 

 1st day (May 25th), 96 eggs; 2nd day (May 26th), 65 eggs; May 

 27th, 138 eggs ; May 28th, 54 eggs ;' May 29th, 33 eggs; May 30th, 

 18 eggs; the female dying the following day. I immediately 

 convinced myself that there were no more eggs in the body, the moth 

 having completed the egg-laying on the 6th day, and I had 404 eggs. 

 On June 8th, 384 larvae had hatched and 20 remained unhatched ; of 

 the moths bred from these larvae, 6 pairs were kept under observation, 

 and the eggs laid by the $ s numbered respectively — 284, 220, 187, 

 160, 121 and 93, i.e., a total of 1065 eggs, with an average of 178 

 for each $ (Lambillion). Bacot considered this decrease in the 

 number of eggs as due to the difficulty of keeping sufficient thoroughly 

 fresh food in a breeding-cage for such a large number of larvae. 

 Eggs are laid singly on leaves of various species of Salix and not in- 

 frequently on apple-trees, the egg stage lasting about 1 1 days 

 (Newman) ; eggs laid singly on the undersurface of willow leaves on 

 the banks of the canal at Hythe (Hill) ; ova laid singly on underside 

 of leaf seldom more than one on each leaf; a 2 that emerged 

 September 2nd, 1900, was paired with a $ that emerged on the same 

 date, and produced fertile ova on the 3rd, these hatched on the 

 19th, but the larvae died before becoming fullgrown for want of my 

 being able to obtain food (Ransom) ; eggs laid on underside of 

 apple leaves at Lee (Bower) ; pearly-whitish eggs laid singly on 

 underside of sallow leaves at Kingsmill (Watkins); ova found in nature 

 on Populus nigra on July 10th, 1892, at Rainham (Burrows); June 9th, 

 1866, $ laid 351 eggs, 38 not deposited=389, at Cambridge, egg- 

 laying lasted 5 days (Gedge) ; eggs on plum-trees at Kensington 

 June 17th, 1847 (Merrifield). 



Ovum*. — Of flat type, micropylar axis horizontal ; i'6mm. long, 

 1 -4mm. wide; pale yellow-green, very shiny, oval in outline, but 

 some variation (occasionally almost circular), the two ends almost 

 equally rounded ; the upper surface with a somewhat circular 

 depression, variable in size, the sloping edges of the depression 

 slightly iridescent ; the surface finely striated longitudinally, very 

 minutely pitted ; the micropyle only traceable as a small depression 

 at one end, the micropylar area apparently similar to rest of egg- 

 shell (Described June 12th, 1899, from eggs laid June 5th, and 

 received from Mr. Hope Alderson). Of a plump oval form, not 

 so deep as wide, upper surface somewhat sunken in middle, the shell 



* Already described (antea, p. 386) in detail and compared with ova of Mimas 

 tiliae and Amoipha popn/i. 



