Development of Estheria Packardi. 



from a rounded prominence, which represents the mandibular 

 body, and are, like the antennae, extended laterally, pointing 

 generally obliquely behind. They are scarcely more than 

 half as long as the antennae, and form each a simple stem, 

 movably articulated to the above-mentioned prominence, and 

 divided into 3 imperfectly defined segments. It is provided 

 with 6 short, spiniform appendages, 3 of which issue from 

 the tip, the other 9 from the inner edge, 2 of the latter 

 being placed close together on the 1st segment. 



The body of the larva is of a greyish white colour, 

 being filled with an opaque granular matter, partly extend- 

 ing into the bases of the limbs. Of inner organs, besides 

 the ocellus, only a very faint trace of the intestine is dis- 

 cerned in the axis of the body. On the whole, as yet only 

 at very slight differentiation of the tissues seems to have 

 taken place. 



The motions of the larva in this stage are still rather 

 imperfect and abrupt. At times it certainly moves the antenna? 

 violently; but, as their setae are still without cilia, the 

 body cannot at any regular rate be propelled through the 

 water, but very soon sinks again to the bottom. It is only 

 after the 1st exuviation has taken place, that the motions 

 acquire that regular and rhythmical character that dis- 

 tinguishes the larva in the succeeding stages. By this 

 exuviation the larva passes immediately into the next stage. 



Second larval stage. 



(PL I, figs. 3 & 4). 



In this stage the body of the larva has become rather 

 more elongated, attaining now a length of 0,34 mm 



