134 COLEOPTERA OF NORTH AMERICA. 



veiy large ; the mandibles very slender, not toothed ; palpi elon- 

 gated, compressed : the middle coxae are contiguous, and the 

 trochanters are less elongated than in the first sub-family. The 

 side pieces of the metathorax are very wide, and the inner margin 

 is straight, or slightly curved. The last ventral segments of the 

 abdomen are provided with a phosphorescent apparatus in the 

 greater number of the species. 



Two sub-tribes exist as follows : — 



Head entirely covered by the prothorax. Lampykini. 



Head partially covered by the prothorax. Luciolini. 



Sub-Tribe 1. — L-anipyrini (genuini). 



The genera found in our territory belong to the group Luci- 

 dot^e, distinguished from the Lampyres, by the females having 

 wings, or at least elytra, though the latter are sometimes very 

 short. 



Second joint of antennae transverse ; 

 Antennae bipectinate ; 



Antennae very short, 14-jointed. Pleotomus. 

 Antennae half as long as the body, 11-jointed. Calyptocephalcs. 

 Antennae serrate, broad, 11-johited. Lucidota. 

 Antennae serrate, 12-jointed, the last joint small. Phausis. 

 Second joint of antennae not transverse, antennae compressed or nearly fili- 

 form. Photinus. 



Pleotomus occurs in Texas. 



Groups of species in Photinus are strongly marked, but accord- 

 ing to Lacordaire are not characterized by differences of generic 

 value. Our species are numerous, and it is in some of those of 

 the third division of Photinus alone, that the females are without 

 wings, and have the elytra much abbreviated. But one species 

 of the first division of Photinus has yet been brought from the 

 Pacific district ; the other genera are not represented in that 

 region. 



Sub-Tribe 2.— Luciolini. 



The wings and elytra are complete in both sexes of all the 

 genera of this tribe, which is represented in our fauna by four 

 species of Photuris, a genus forming by itself a group distinguished 

 by the head being narrowed behind, and by the labrum being 

 indistinct, characters which approximate to the Telephoridas. 

 The species are confined to the Atlantic district. 



