278 t'^^y- 
notes, carefully made by Mr. Buckler, is to bring together their distinctive marks 
more fully. 
They are all shortish, smooth loopers, coloured with various tints of green. 
Th. simulata. About ^ inch in length j stouter than the others. Head 
yellowish-green ; back pale greenish-blue ; dorsal line slender, of dull grass-green ; 
sub-dorsal stripe of same colom' ; below this comes a white stripe, and then a broad 
stripe of the dark green, reaching to the spiracles, and there edged with dark 
brown ; between this and the legs is a pale yellowish stripe : legs greenish. 
Th. oheUscata. Same length ; anal segment pointed, and very minutely bifur- 
cated at extremity ; head bent under, in colour green ; back bluish-green ; dorsal 
line darker green, and edged with lines paler than the ground colour ; sub-dorsal 
line commencing on second segment as a yellowish-white line, then widening into 
a broad stripe, and assuming a blue tinge edged with white, till the tenth segment, 
when it contracts, and assumes the yellowish tint again ; below the spiracles a 
fine yellowish-white Hue, but broader at each end ; belly green, with a central 
yellow line, and on either side an indistinct whitish line. Legs tinged with red. 
Th. firmata. Same length ; anal segment decidedly forked ; head slightly 
bent under, red, with a brown streak over each lobe. Ground colour dark bluish- 
green ; dorsal line of a much dai'ker tint of the same ; sub-dorsal line whitish, fine 
and uniform in width, quite white on second segment ; below the spiracles a fine 
whitish line, tinged with yellow on the hinder segments ; belly green, with three 
equidistant pale Hues. — J. Hellins, 23rd Jaiiuary, 1867. 
Note on variation in Lepido;ptera. — Dr. Knaggs, in his interesting remarks on 
this subject, makes no mention of the effect produced on Le]pidoptera by the size 
and ventilation of the cages in which they are bred. This seems to me a constant 
cause of variation in size of bred specimens ; want of room and ventilation producing 
small examples. I have bred in a box 3|-in., 2J-in., and 2-in. deep, covered with 
glass, specimens of Odonestis potatoria, the ? measuring only 1" 10"' in expanse, 
Arctia caja 1" 11"', Clostera anachoreta 10"'. The only cause I can assign for this 
diminution in size was the want of room in the breeding cage. In no instance was 
the insect forced, but in each case remained the usual time in the larval and pupal 
stages. That this suijposition is correct, I am fm^ther convinced by the fact that 
larvae of the same batch that produced the above Rotatoria and caja, reared in a well 
ventilated cage, produced large specimens. If this hypothesis be correct, may it 
not be applied to insects in their natural state, and account, to some extent, for 
the usual difference in size of the spring and summer broods of S. illustraria ? 
May not the larvas produced by the summer brood " feed up " more leisurely than 
those of the spring brood, and thus have more time to roam about, which exercise, 
aiding their development, cause them to produce larger images ? — James A. Fokster, 
38, Skinner Street, Clerkenwell. 
Note on the contructility of the silk of leaf-rolling larvas. — At page 15 of our 
second volume, my friend, Bernard Piffard, treats us to an interesting little note on 
leaf-rolling, which I had hoped would have elicited some further remarks. The 
interest attaching to this subject, and the approach of the season at which investi- 
