456 ENTOMOLOGICAL NEWS. [Dec., 'll 



TRANSFORMATION. 



As related on page 407 the larvae collected at Juan 

 Vinas were brought to Cartago and placed in glass tumblers, 

 The opening of each tumbler was covered with a piece of net- 

 ting. In the early days of April, 1910, we noted that some of 

 these larvae showed signs of approaching metamorphosis, so we 

 took care that some leaves of the small bromeliad in each glass 

 touched the netting and thus afforded a means whereby the 

 larva could reach the latter and there attach itself for transfor- 

 mation. 



On April 4 larva No. 59 had so attached itself and at 8.15 A. 

 M. the splitting of the cuticle on the thorax began. By 8.30 A. 

 M. the thorax, head, legs, wings and first four abdominal seg- 

 ments were disengaged and hanging from the exuvia which 

 was attached to the under side of the netting, the body of the 

 imago being sustained entirely by the hind end of the abdomen 

 which was still within the exuvia ; the wings were about 10 

 mm. long. At 8.40 A. M. the imago was completely free from 

 the exuvia and clinging to the netting by its legs. In the mean- 

 time we had set up our camera in a convenient position in our 

 room ; then pinned the netting cover with the exuvia and ex- 

 panding imago on it to the door of the wardrobe and obtained 

 the photographs which are reproduced as figure 8, Plate XVIII, 

 and figures i-S, Plate XIX. The imago made its first flight at 

 1.53 P. M. It lived in captivity until April n. 



Larva No. 55 transformed April 6 and, with the experience 

 obtained from No. 59, we were able to secure photographs of 

 earlier stages in metamorphosis (PI. XVIII, figs. 3-7). The 

 whole series of figures on these Plates, together with their ex- 

 planation, may dispense with further description here. As will 

 be seen from an examination of them, the great length of ab- 

 domen of the imago is a relatively sudden acquisition and is not 

 foreshadowed by the size of the larva. This may be still more 

 appreciated by comparing our figures with those of the trans- 

 formations of other Odonata as given, for example, by Latter 

 (1904) and Ward (1910). The decrease in thickness of the 

 abdomen between the stages represented in PI. XIX, figs. 6 and 

 7 is also noteworthy. 



