FIREFLY GENUS PYRACTONEMA — McDERMOTT 151 



lugubris, and P. obscura. P. bardelli and P. bioculata are described 

 as brown, not black, and P. brevipennis differs only in the short elytra. 

 In nigripennis the thoracic coloration is described as yellow, but 

 Olivier's (1907) illustration shows it as red. One specimen in Pefia's 

 collection had yellow instead of red, as did some of those in the Cali- 

 fornia collection, while one specimen of P. vicina, as noted, had red 

 instead of yellow. Apparently yellow and red colorations are alterna- 

 tive in this genus. P . fissicollis may be dismissed as an abnormality, 

 as noted by Olivier (1899). There were several hundred specimens 

 representing this group in the material sent to me by Pena, the speci- 

 mens ranging from 5 to 19.5 mm. long in the males and up to 24 mm. 

 in the females. What bearing this situation has on taxonomy is 

 discussed under the species descriptions. 



In view of the great superficial similarity of the specimens (or 

 species) in this group in characters other than size, a general 

 description is given below that will apply to all; under the three 

 species are given the dimensions of the admittedly arbitrary divisions 

 for each. The smaller specimens appeared to be somewhat broader 

 proportionately than the larger ones, a difference confirmed by the 

 final measurements. 



Pronotum with wide lateral and apical, narrow basal borders, 

 and wide median longitudinal vitta black. Portions of apical edge in 

 front of eyes may be brown. Disc with two subrectangular or 

 reniform red areas (rarely yellow), the color not being particularly 

 brilliant. The median vitta is broader in the females than in males 

 and in P. nigripennis usually has an urn-shaped outline. The red 

 area comprises 0.3 to 0.5 of the total surface. Basal edge usually 

 sinuate, angles various. Lateral edges deeply and apical margin 

 usually slightly reflexed. A depression just forward of each red spot. 

 Shallow sulcus, frequently wide, in basal half or third. 



Scutellum black. Mesonotal plates black to very dark brown. 



Elytra black, tricostate in larger specimens, the costae becoming 

 less pronounced in the smaller specimens. Explanate margins very 

 narrow, about one-seventh or less of the elytral width In males longer 

 than the abdomen or ending with it; in females usually exposing 

 1 to 4 abdominal segments. Elliptical outline. 



Head with frons black, usually projecting more or less bulbously 

 between the antennal sockets. Eyes relatively small, the distance 

 across them being about 0.55 to 0.6 of the pronotal width. Clypeus 

 short, black, hairy, semicircular, or medially cmarginate. 



Antennae black, compressed. Articles 3 to 10 subrectangular, base 

 about 0.6 of apical width. Base of 4 to 11 attached near to the 

 outer apical corner of the preceding article in the males, the point of 

 attachment being more nearly median in the females. Vestiture 



