124 
DoBsoN^ on Laap, or Lerp. 
the exclusion of the larva^ the egg bursts longitudinally from 
its free extremity. The body of the larva is nearly trans- 
parent^ except the eyes and dorsal vessel,, and resembles in 
form that of the subsequent pupa. An early stage of the 
pupa's growth is shown in fig. 2. A thick uniform cylindrical 
thread of a transparent viscous fluid issues from the anal 
aperture^ and terminates in a considerable globule. 
Finer filaments proceed from between the rings of the 
abdomen^ near the extremity of which are two principal 
excretory glands. At almost every articulation of the body 
and limbs the microscope reveals minute globules of this 
white fluid. 
Four lateral tubular cases contain the rudimentary elytra 
and wings. 
Fig. 2 also exhibits the first framework of the conical roof. 
Portions of the strong central thread have been turned up 
the back by the bifurcated tail, one extremity of each por- 
tion rests on the leaf, the others meet together and form a 
rough apex to the framework over the back of the insect. By 
turning round its body the finer filaments are passed from 
rafter to rafter in the inside, until they form an open basket- 
like covering, and combine into one thin glutinous cup-like 
sheet. The subsequently secreted fluid oozes out in drops at 
the base, and hardens and elevates the original roof on 
the wall formed by these accretions. This occasions the 
appearance of superposition, and the lateral displacement 
of the apex observed in most of the specimens of old lerp. 
(Fig. 5.) 
When the pupa is about to undergo its final transformation, 
it escapes from its skin through a fissure down the back, eats 
its way out of the cone through a round hole, and leaves the 
skin within. 
But when the base is not too firmly attached to the leaf, 
the pupa creeps out from beneath, and throws off its skin on 
the leaf. The perfect insect is represented in fig. 4. The 
antennae are filiform, and have ten articulations. The two 
first are much shorter and thicker than the others, and the 
last is terminated by two hairs. Two elongated parallel tubes 
compose the " sucker,^' as it is improperly called, with which 
the insect pierces the leaf, and procures its juices. The eyes 
are prominent, globular, and compound. Immediately behind 
each eye is an ocellus. In many individuals a third ocellus 
appears in the central furrow which divides the head longi- 
tudinally, and therein they agree with the general character 
of the genus according to Latreille, Milne Edwards, &c. ; but 
in others, as in fig. 4, this central ocellus is replaced by two 
