( iv ) 
Fig. 3 is a larger box, of just double the depth of the others, 
measuring 9 in, by 6 in. by 6 in., with a diagonal partition 
forming a single trough above and below (/«, i), capable of 
carrying envelopes of a larger size. 
Fig. Irt. 
(In Figs. Iffi, 2 and 3, the two lids have been omitted, for 
sake of clearness.) 
These boxes are designed for three sizes of envelopes, which 
gives a sufficient range for butterflies of any size. Size 1 is 
made from a rectangle 8 in. by 5 in. Size 2, from a rect¬ 
angle 6 in. by 4 in. Size 3, from a rectangle measuring 4 in, 
by 2| in. 
