454 BRITISH I.EP1D0PTERA. 



They commenced to hatch on the 24th, 59 larvae resulting. Of the 

 other 104 eggs, 55 appeared to have fully developed, but from some 

 unexplained cause had not emerged ; 27 were still green (these after- 

 wards dried up), and of the remainder some were very discoloured 

 (probably died during the development of the embryo), and others 

 had shrivelled up without change (probably unfertilised). 



Ovum. — Exactly the same as that of Amorpha populi. 



Larva. — First stadium (June 29th) : Length between one-eighth 

 and three-sixteenths of an inch when newly hatched, growing to 

 between three-eighths and seven-sixteenths before the first moult. 

 Head : green, large, rounded, but with a tendency to triangular shape ; 

 a few scattered hairs and a yellow inverted V on face. Body : pale 

 green ; scutellum fairly distinct ; a faint, dark, mediodorsal line ; two 

 tubercles on the dorsal area of the thoracic segments can be distin- 

 guished as rather larger, and bearing longer hairs than the usual 

 shagreen mammillary points. The trapezoidals on abdominal seg- 

 ments can also be observed standing out among the mammillary 

 points, though not quite so clearly as the two mentioned above 

 as being on the thoracic segments. (This last feature is not dis- 

 tinctive of the hybrid larvae ; it can also be seen in the larva of 

 Smerinthus ocellata, and is probably present in those of Amorpha populi 

 and Mimas tiliae. I merely call attention to it as an important 

 point that I had not previously noted.) Seven oblique stripes are 

 present, the seventh being rather stronger than the rest ; the subdorsal 

 lines distinct. All the stripes are more conspicuous after the larva has 

 been feeding for a few days. Caudal horn : long, pale pink ; some of 

 the larvae have only short horns, which appear withered (in one instance 

 almost to the stump, in another it is almost entirely absent, while a 

 third has the horn constricted just above the base, as though a piece 

 of thread had been tied round it). I have noticed a similar deformity 

 to this last in a larva of M. tiliae. [Unfortunately, I had no larvae 

 of either S. ocellata or A. populi "in the first stage with which to com- 

 pare, but, judging from memory and written descriptions, I noted as 

 follows : The larva closely resembles that of 6". ocellata in shape 

 and attitude, as well as in markings.] Second stadium (July 3rd) : 

 Most of the larvae are now in the 2nd stadium, and are growing 

 rapidly. [By this time I had larvae of both S. ocellata and A. populi 

 in the same stage as the hybrid larvae, so that the comparisons 

 in this and subsequent stages are more exact.] Length, three- 

 eighths to five-eighths of an inch. Head : triangular, broader, less 

 tall and pointed than in larva of £". ocellata, but not so bulged 

 at cheeks nor squat as in that of A. populi; yellow mammillae at 

 apex of head taller than in the latter species. Body : scutellum 

 indistinct; the subdorsal stripes are continued faintly across the 

 oblique lines to the 5th (in one larva to the 7th); the mediodorsal 

 line is produced by the absence of shagreen mammillae ; dark 

 borders to oblique lines are present. The stripes are stronger 

 than in A. populi, but not so marked as in 6*. ocellata. In addition to 

 the other stripes, there is a faint lateral line below the subdorsal, 

 on the thoracic segments. Caudal horn : the base is pink for 

 about one-third its height ; shorter and lighter in colour than that 

 of ^. ocellata, though more marked in both respects than in larva 

 of A. populi. [Habits : The larva retracts the first two pairs of 



