LAMPYRIDAE. 207 



student to ascertain in this group, to what goiiiis his si)ecitncn 

 should be referred, before he attempts its specific determination. 

 There are in many families of Coleoptera strong resemblances 

 between species of different genera, but there are none (with tlie 

 exception of certain Khynchophora), so deceptive as those which 

 our own limited fauna presents to us in this group of Lanipy- 

 ridEe. 



Eyes small; light organs feeble; ventral segments without stii;ma-like 



pores. 2. 



Eyes large, but larger in % than J ; light organs well develoi^ed ; % with 



strongly marked stigma-like ventral pores. .'J. 



2. Antennae with second joint one-half as long as third or nearly so. 3. 

 Antennae very much compressed, not serrate, second joint very short, 



transverse. Lucidota. 



3. Antennae not serrate, narrow, compressed. 4. 

 Antennae strongly serrate (^9), prothorax snbcarinate, dorsal seg- 

 ments strongly lobed, % last dorsal broadly emarginate. Tenaspis. 



4. Last dorsal segment % rounded. Ellychnia. 

 Last dorsal segment % bisinuate and truncate. Pyropyga. 



5. Prothorax subcarinate ; J with lateral light organs. Pyractoniena. 

 Prothorax not carinate, frequently channelled; f with medial liglit 



organs. Photinus. 



Group III. - Lampyres. 



A sufficient character for separating this group is found in the 

 last joint of the antennae which is usually appendiculate, rarely 

 (Pleolomufi) sinuate near the tip. The joints of the antennas vary 

 in number as well as form. The sexes are dissimilar; the 9 is 

 frequently larviform with very short scale-like elytra; the light 

 organs seem to be always brilliant in the 9, but variable in the % . 

 sometimes well developed (Phaiisis i-eticulota) sonietimes want- 

 ing (P. inaccenaa). The eyes of the % are very lai-ge, cdutigu- 

 ous or nearly so, both above and beneath. In the 9 they are 

 moderately large {Pleotomiai) or very small {Jhcrophotus). 



Antennae bipectinate, 14-jointed, very short and compact in the 9; eyes 

 moderately large in 9, very large and nearly contiguous in tin- -J, ; 9 

 with very short distant elytra. Pleotomus. 



Antennae simple, with quadrate joints ; eleventh joint with an articulated 

 acicular appendage ; 9 with short elytra; prothorax with transparent 

 spots. Phausis. 



Antennae short, simple, with qnadrate joints; 9-jointed (%), or 8-jointed 

 (9) ; eyes very large, contiguous (%), very small, transverse, distant 

 (9) ; elytra of 9 very short, rounded. Microphotus. 



