176 THE CANADIAN ENTOMOLOGIST, 



It is then sufficient to say, that none of the Lycidae or Telephoridae 

 possess any light-giving organs, and that they are diurnal in their habits. 

 In some of the Lycidae the front part of the head is prolonged into a 

 beak, and in many of them the elytra are very large, expanded and 

 coarsely reticulated. The peculiar structures of some Telephoridae will 

 be noticed farther on. 



The Lampyridas proper comprise all the luminous species, though this 

 faculty is possessed by them in a very unequal degree, and in some genera 

 and species of diurnal habits is quite wanting. For our present purposes 

 their division may be indicated into tribes and groups as follows : 



A. Side pieces of metathorax narrow ; 



a. £ and ^ similar or nearly so ; antennae long, last joint simple. 



b. £ and $ conspicuously different ; antennae short, last joint with 

 acicular appendage. 



B. Side pieces of metathorax wide ( °. unknown) ; palpi very 

 unequal, mouth organs more developed. 



The series A a contains the largest number of genera and species, and 

 exhibits a gradation from Matheteus, with widely separated pectinate 

 antennae, and general Lyciform appearance, through Photinus, with 

 approximate filiform antennae, and head retracted under the prothorax, to 

 Photuris, with the antennae filiform, and the head partly exposed. There 

 is thus a continuous line of affiinities in this series from the diurnal 

 Lycidae to the diurnal Telephoridae. 



Now besides the gradations in structure just mentioned there are great 

 differences in the sizes of the eyes, and in the development of the light 

 organs. In the species usually seen flying by day (Lucidota, EUychnia, 

 &c ) the light organs are indicated by feeble yellowish spots on the last 

 ventral segments, but do not seem to possess any light-giving power ; in 

 these the eyes are lateral, rather small in % , but larger and more convex 

 in £ ; they are widely separated above and beneath as in Lycidae. 



The series A b contains a much smaller number of genera, and in 

 them the antennae are approximate, usually filiform, rarely (Pleotomus) 

 bipectinate. The number of joints varies from 9 to 14, and the last joint 

 has at the end a small acicular appendage simulating an additional joint. 

 The eyes of the £ are excessively large, almost contiguous above and 

 beneath, leaving very little room for the mouth and antennae ; in the £ 

 the eyes are moderate, or even small, lateral and widely separated. The 



