FIREFLY GENUS PYRACTONEMA — McDERMOTT 141 



Pyractonema albomarginata Solier 



FlGUKE 1 



Pyractonema albomarginata Solier, in Gay, Hist. Pis. Pol. Chile, vol. 4, Zool. 

 p. 447, 1849. 



Material: 51 specimens, of which 45, including 10 females, were of 

 the typical variety, and G including 4 females were smaller. The 

 latter are not given a varietal name, however, as it seems probable 

 that intermediates will be found. 



General: A small, nonluminous lampyrid easily distinguished by the 

 white-margined elytra . 



Dimensions: Typical males 7.G5 to 11.65 mm. long by 2.35 to 2.42 

 mm. broad, average 9.4 by 2.9 mm. Females 6.75 to 9.6 mm. long 

 by 2.45 to 3.45 mm. broad; average 7.9 by 2.9 mm. Smaller males 

 6.66 to 6.98 mm. long by 1.89 to 2.29 mm. broad; average 6.8 by 

 2.1 mm. Smaller females 4.72 to 6.45 mm. long by 2.02 to 2.55 mm. 

 broad; average 5.69 by 2.28 mm. 



Pronotum of males 1.2 to 1.7 mm. long by 1.92 to 2.6 mm. broad. 

 General outline semicircular or semielliptical, sometimes a little ex- 

 tended apically especially in males, with a transverse subrectangular 

 red spot occupying about half of the total area and not quite reaching 

 the base. Marginal borders translucent, reflexed at sides and apex, 

 rather coarsely and closely punctate. Basal border narrow. In oc- 

 casional specimens the lateral and apical edges brown, the infuscation 

 of the latter sometimes long-triangular, apex forward. One specimen 

 had two black spots at lateral thirds adjacent to the posterior edge. 

 Disc smooth, occasionally inflated, median channel sometimes in- 

 fuscatc. Posterolateral angles very variable, from dull rounded to 

 acutely produced. Basal margin usually slightly sinuate, sometimes 

 circularly curved. Maximum width usually from just forward of the 

 angles to basal fifth. Females similar but relatively slightly wider 

 and angles less prominent. 



Scutcllum black. One specimen had a small median red spot, and 

 another a long red mark in the apical half. Mesonotal plates black. 



Etytra black, with narrow, translucent white lateral borders, 

 widened apically. No sutural borders. Subparallel to apical third 

 or fourth, then tapering in lateral margin. Occasionally slightly 

 widest at about midlength. Verj aarrow explanate margins. 



Head black. Antenna! sockets white or pink. Eyes small, width 

 across them about 0.75 to 0.8 of pronotal width. Clypeus short, 

 dark brown, usually feebly emarginate. 



Antennae black. Articles 3 to 11 very compressed and of about 

 equal length. 



534087—60 2 



