LAMPYRIDAE. 205 



Sub-Family II.—LAMPYRIN.E. 



The species of this sub-family are easily separated from the 

 Lyeida? by the middle coxae being contiguous, and the epipleurai 

 wide at the base of the elytra, even when the latter as in some 

 9 9 are very short. 



From the Telephoridae they are known by the metathoracic 

 episterna being sinuate on the inner margin, a character first 

 observed by DuYal, and which seems to have much value in 

 apportioning the more difficult forms to their respective groujjs. 



The genera examined seem to indicate two tribes; the first is 

 numerous on both continents, especially in the tropical regions; 

 the second is perhaps exclusively American, unless it can be 

 united with Driliui. 



Head more or less covered, anteiinse api^roximate or moderatel}' distant ; 

 metathoracic epimera long. Lampyrini. 



Head exposed, antennae distant ; metathoracic epimera wide. 



PlIEXGODINI. 



Tribe I.— LAIWPYRIXI. 



The most characteristic structure in these insects is the light- 

 giving apparatus which is contained in the posterior abdominal 

 segments of most of the species, though it is quite absent in some 

 genera. 



The position and form of the organs differ according to genus 

 and in a less degree according to species. 



In most of the genera the sexes are similar in appearance, but 

 in the Lampyres group the 9 are larger than % and larviform, 

 with short elytra and no wings. In these genera the eyes of the 

 % have their maximum, and those of the 9 the minimum develop- 

 ment. In the other groups the eyes of the % , though larger than 

 those of 9, are not remarkable or disproportionate in size. The 

 head is deeply immersed in the prothorax which is foliate at the 

 sides and apex, so as to protect the head. 



The antennae are approximate or moderately separated, and 

 vary in form according to group and genus. Our genera seem 

 to indicate the following groups: — 



Antennae with second joint small, usually transverse, head completely 

 covered by prothorax. 



Antennae pectinate, rather distant, last joint simple. Mathetei. 



Antennae not pectinate (in our genera), approximate, last joint elongate, 



simple. PuoTiNi. 



