BIOLOGY OF SOME COMMON LAMPYRID.E. 41 



that the female, in responding to the flash of the opposite sex, 

 always turned the ventral side of her abdomen, so that it would 

 emit light in the direction of the male. 



Fabre (1913) maintained that the glow-worm, in feeding on 

 snails, injected a substance in the nature of an anaesthetic which 

 paralyzed its host. 



Vogel (1915) did by far the best biological work that has been 

 done on this group of insects. He described the external and 

 internal anatomy of the larva of Lampyris noctiluca, together 

 with its life-history. He observed that the larva lived in the 

 ground, and that it fed on snails. By making a careful study of 

 the structure of the mouth-parts, pharynx and gizzard he found 

 that the digestive juices of the mid-intestine were emitted through 

 the hollow mandibles. By this means the larva was able to 

 paralyze its prey, and to digest the tissues before eating them. 



Haddon (1915) described also the process of feeding and the 

 nature of the mouth-parts of Lampyris nocliluca. 



Blair (1915) and Morse (1916) reported the interesting phe- 

 nomenon of the synchronous flashing of fireflies, in which the 

 fireflies in a given locality were found, at times, to flash in unison. 



Williams (1917) described the life-history of several of our 

 common Lampyrids. His discussions of the biology of Phoiinus 

 consanguineus and Photurus pennsylvanica are especially valuable. 



Photinus consanguineus Lee. 



The insects of this species are elongate and slender with the 

 head covered by the prothorax. The prothorax is rounded on 

 the anterior and lateral sides, truncate behind with the angles 

 acute. It is light yellow with a black median bar, which is 

 bordered with pink on either side. The elytra have wide side 

 margins and bear two or three sub-obsolete carinae. The suture 

 and side margins are pale yellow, while the remainder of the 

 elytra is grayish in color. They are granulate and rather pilose. 

 The abdomen in the male is depressed, but in the female it is 

 often rounded, due to being distended with eggs. The eyes 

 of the male are larger and better developed than those of the 

 female. The light-organs of the male cover the entire sternites 

 of the sixth and seventh abdominal segments, while in the 



