Packard.] 396 [February 26, 



oblong ai'ea, when before it was triangular, owing to the absence of the 

 A-shaped pair of tubercles, which are now concealed from view. The 

 eighth urite, still more triangular and pointed, covers them in. The 

 mesial parallel pair are much changed in form, since they are each 

 curved outwards, and diverge at both extremities like an X. Upon 

 pulling the whole apparatus, with the neighboring rings, out like the 

 section of a telescope, we find that it has greatly increased in size, 

 and that it has become wholly separated from the rest of the abdo- 

 men, being attached by its integuments, and that the V-shaped 

 parts of the tubercle are obsolete. The base is partially covered 

 above by the obtusely triangular tergite, and below by a thin, square, 

 lamellate, finely setose urite. The bases of the outer larger pair of 

 hook-like organs are inclosed in the remnants of the ninth ring. It 

 is short, complete above, but becomes obsolete beneath. The outer 

 hooks, or rhabdites, are three times as long as broad, and consist of 

 two portions ; one basal, and the other terminal, and provided with 

 several hooks. At their bases they approach each other very closely, 

 only a slight fissure intervening; then they suddenly narrow towards 

 the middle, and continue of the same width to the end; both sides 

 are parallel and curve inwards so much that the tips are near to each 

 other, by a distance equal to the breadth of either of the pieces. 

 The terminal piece which, in reality, is nearly square, consists of two 

 portions separated by an oblique suture, of which the outer piece is 

 the smaller, and terminates in a sharp slender booklet, bent inwards 

 itself, and placed on the inner side, next the hooks of the inner and 

 middle pairs of organs. 



The inner pair of booklets, which are long, slender, and curved 

 inwards and downwards, arise parallel to the base of the outer por- 

 tion of the outer pair of hooks. The basal portion to which they are 

 attached are united to form an oval fleshy piece, which is a23i3arently 

 thrust out from between the outer jiair of hooks. 



Viewed from beneath, the outer pair of hooks ai'e smaller and 

 shorter, in form more triangular, with more acute and incurved tips, 

 which inclose a broader interspace. The outer portion of the hook 

 described above, does not appear on the lower side. On the con- 

 trary there is a deep suture beneath it, and thus there is another 

 longer piece which forms a hook-like prolongation on the under side 

 of the basal piece. 



In the young of JEschna and Agrion the development of the ovi- 

 positor seems to be much the same. In the pupa of 

 ^ ^Eschna, the first pair (a) of rhabdites arise from 

 the eighth urite (Fig. 7), and the tAvo other pairs, 

 6 arising from the ninth urite, are closely appressed to 

 the body, the tips of the outer (c) of the two pairs 

 F'g. 7. being free. 



