LUMINOUS INSECTS. 40? 



three last ventral segments of the abdomen a ; I shall 

 give you the result of some observations I once made 

 upon this subject. One evening, in the beginning of 

 July, meeting with two of these insects, I placed them 

 on my hand. At first their light was exceedingly bril- 

 liant, so as to appear even at the junctions of the upper 

 or dorsal segments of the abdomen. Soon after I had 

 taken them, one withdrew its light altogether, but the 

 other continued to shine. While it did this it was laid 

 upon its back, the abdomen forming an angle with the 

 rest of its body, and the last or anal segment being kept 

 in constant motion. This segment was distinguished by 

 two round and very vivid spots of light; which, in the 

 specimen that had ceased to shine, were the last that 

 disappeared, and they seem to be the first parts that be- 

 come luminous when the animal is disposed to yield its 

 light. The penultimate and antepenultimate segments 

 each exhibited a middle transverse band of yellow ra- 

 diance, terminated towards the trunk by an obtusely- 

 dentated line ; a greener and fainter light being emitted 

 by the rest of the segment. 



Though many of the females of the Lampyrida are 

 without wings and even elytra, (in which circumstance 

 they differ from all other apterous Coleoptera,} this is 

 not the case with all. The female of Pygolampis^ ita- 

 lica, a species common in Italy, and which, if we may 

 trust to the accuracy of the account given by Mr. Waller 

 in the Philosophical Transactions for 1684, would seem 



a Geoffr. i. 167. De Geer, iv. 35. 



b I call by this name all those Lampyridcs whose head is not at 

 all, or but little, concealed by the shield of the prothorax, and both 

 sexes of which are winged. 



