82 Mr. A. S. Packard on the Development 



pairs of feet. Eggs agglutinated, and forming a broad flat 

 mass. 



Sp. Leposphilus Lahrei. 



Colour varying from yellow to pale red. Length about 10 to 

 12 millims. Male unknown. 



Inhabits the Green Wrasse, in the scales of which it hollows 

 out a retreat. 



XV. — Observations on the Development and Position of the Hy- 

 menoptera, with Notes on the Morphology of Insects. By A. 

 S. Packard, Junr., M.D.* 



The following notes form an abstract of a more extended memoir 

 upon the changes of the insect after leaving the egg, not touch- 

 ing upon the evolution of the embryo. 



After the larva has become full-fed, as it is about to enter 

 upon the semipupa state, its body undergoes the following 

 changes: — The thoracic rings and head become more elongated 

 and fuller, so that whereas in the larva the underside of the an- 

 terior and posterior halves of the body are closely appressed to 

 each other, now the two halves begin to recede, and the grub, as 

 it lies in its cell, is but half doubled upon itself. With this im- 

 portant change of posture, the whole body becomes more cylin- 

 drical and rounded. Thus the sides (arthropleurse) of the 

 thoracic ring become absorbed, and do not project out from the 

 walls of the body as in the larva; and later still, the corre- 

 sponding area in the abdomen likewise almost wholly dis- 

 appears. 



The greatest activity, however, is observable about the cephalic 

 portion of the body; for here the greatest differentiation of parts 

 is to occur. The head of the pupa, already partially formed 

 beneath the prothoracic ring, though as yet very small, by its 



f)resence still affects very sensibly the form of this region in the 

 arva, the skin of which still remains unbroken, though very 

 considerably distended. The whole length of the head (tig. 1 a) 

 and prothorax (fig. ] b) together is now equal to the united 

 length of the head and thorax in the larva originally. To effect 

 this, the larval head is greatly extended forwards, and the pro- 

 thorax is three times as long as before, and much narrower, the 

 sides converging towards the base of the head. The two pos- 

 terior thoracic rings are also twice as long as in the larva. On 

 the under (sternal) side the mouth-parts are also elongated ; and 



* Communicated by the author, from the * Proceedings of the Boston 

 Natural History Society,' Feb. 7, 1866. 



