to some American species of Lampyris. 123 



During the intervals, a very singular appearance pre- 

 sented over the whole luminous portion, entirely invisi- 

 ble to the naked eye. From the points of the villi co- 

 vering the whole scutum, infinitely small sparks of light 

 seemed to issue, forming a kind of creeping scintillation, 

 not unlike the appearance of burning paper, after the 

 blaze has been extinguished. 



This, I believe, is the cause of the partial shining, as 

 it appears to the naked eye, during the interval between 

 the flashes, and can only be perceived in the dark. 



In the day-time, nothing of the kind can be discerned. 

 The substance contained under the scuta is of an opake 

 white colour, and evidently cellular. Its construction 

 bears a considerable analogy to the membrana adiposa of 

 the human subject, but is more delicate. In one or two 

 instances, I thought I could perceive something similar 

 to the ramifications of the bronchia, appearing to origi- 

 nate from the spots, which I took to be perforations, in 

 the scuta. 



In three cases, I succeeded in dividing the insect ex- 

 actly across the spots, without hurting it, by a very 

 sharp instrument, but this appearance I did not often 

 sec. 



