the Cup- like Coverings <?/ Psyllidee, d:c. 237 



turned up tlie back by the bifurcated tail, one extremity of 

 each portion rests on the leaf, the others meet together and 

 form a rough apex to the frame-work 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 leri>. (Fig. 3 a.) 



When the pupa is about to undergo its final trans- 

 formation, 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. Imme- 

 diately behind each eye is an ocellus. In many individuals 

 a third ocellus appears in the central furrow which divides the 

 head longitudinally, 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 ocelli separated by the furrow. 

 This duality of organ accords well with analog}^ and 

 disposes me to believe that what has been hitherto con- 

 sidered a third central ocellus is really a combination of 



s 2 



