98 MODERN CLASSIFICATION OF INSECTS. 
charge a clear greenish watery fluid, from lateral pores placed above 
the spiracles, to a considerable distance. This, however, only takes 
place when the insects are in a state of nature, and is exhausted after 
seven or eight discharges. (Fennell, in Mag. Nat. Hist. No. 32.) 
These larvee always rest on the upper surface of the leaf, rolled up in 
a spiral direction, the tail occupying the centre. They attain a con- 
siderable size; and, when full grown, they construct a strong parch- 
ment-like cocoon of a brown colour, which they attach to the branches 
of the trees upon which they have been feeding, or beneath fallen leaves 
on the surface of the earth, and in which after remaining a consider- 
able period in the larva state, they are changed to inactive incomplete 
pupz, which state lasts but a short time. De Geer ( Wémoires, tom. ii. 
tab. 33. f. 1—16.) and Lyonnet (Posth. Mém. pl. 15. f. 20—29.) have 
published complete details of the transformations of Cimbex lutea ; 
and in De Geer’s figs. 17—24. are given those of Clavellaria amerinz. 
His tab. 34. f.1—8., and Hartig (pl. 1. f. 1—23.) represent Cimbex 
femorata (variabilis) in its different states, with elaborate details. It 
is in the months of August and September that the larva of this insect 
is to be found on the alder, birch, and beech. From the diversity of 
its food, Dahlbom states that varieties in the imago, which have been 
regarded by Leach and others as distinct species, have been produced. 
Drewsen (in Ann. Soc. Ent. de France, 1835, p. 169.) has communi- 
cated some observations proving that this insect ordinarily remains 
two years in its cocoon. Frisch (Beschr. Ins. Deutchsl. vol. iil. p. 25.), 
Albin (Nat. Hist. Engl. Ins. pl. 59.), Dahlbom in Wetensk. Acad. 
Handl. 1834, and Roesel (Jus. Belust. vol. ii., Bomb. and Vesp., 
tab. 13.) have represented the transformaticns of this species, whilst 
those of Claveilaria amerinz have been also described by the last 
author ( Op. cit. tab. 1. f.1—4:., and tab. 2.; and by Geedart, Jus. tom.i. 
pl. 64.). In its earlier stages its larva are gregarious, but by degrees 
they become more and more solitary. Its cocoon is not so strongly 
formed as that of Cimbex femorata, and is reticulated. Lyonnet 
(Posth. Mém. pl. 16.) has given complete details of another large 
species of Cimbex, which De Haan gives as C. sylvarum; but, both 
in his pl. 15. f. 20. and pl. 16. f. 1., the larvae are represented incor- 
rectly, the apodal segment succeeding the metathoracic segment being 
omitted. 
The larvee of Trichiosoma lucorum (fig. 69. 12.) are not of uncom- 
mon occurrence on the white thorn at the beginning of August. From 
