92 U. S. NATIONAL MUSEUM BULLETIN 216 



strong dorsolateral raised flanges; frons often with a median tubercle 

 between the interantennal process and the median ocellus; clypeus 

 margin weakly arcuate, a little raised away from base of labrum; 

 upper tooth of mandible acute and connected with the ventral condyle 

 by a prominent ridge; lower tooth of mandible small or minute, 

 strongly impressed so that it is difficult to see and the mandible appears 

 twisted; maxilla and labium short; temple almost flat; occipital carina 

 very close to foramen magnum, complete; prepectal carina weakly 

 angled above the sternaulus, more dorsad reaching almost to sub- 

 tegular ridge, gradually approaching but ending well separated from 

 front edge of mesopleurum; second recurrent vein with one bulla; 

 hind femur about three times as long as deep; tarsal claws apparently 

 simple; first tergite rather small, in profile flat or weakly rounded 

 dorsally and roundly declivous basally; male clasper convex, without 

 a lateral ridge. 



Subgenotype: Metopius errantia Davis. 



Of this subgenus we have seen the Mexican Metopius scutatifrons 

 Cresson 1874 (new combination in Peltales), four undetermined 

 Neotropical species, and the two Nearctic species treated below. 



Key to the Nearctic species of Peltales 



1. Mesoscutum entirely black; punctures on mesopleurum large, separated by 

 about 0.7 their diameter; frons with an acute tooth below median ocellus. 



1. errantius Davis 

 Mesoscutum black with 2 longitudinal yellow lines which are connected 

 posteriorly; punctures on mesopleurum rather small, separated by about 

 1.5 their diameter; frons with a weak swelling below median ocellus. 



2. not at us, new species 



1. Metopius (Peltales) errantius Davis, new combination 



Front wing 6.3 to 8.5 mm. long; facial shield about 1.0 as high as 

 wide, its point distant from apical margin of clypeus; interantennal 

 process about 0.65 as high as wide, dorsally adnate to frons in female, 

 somewhat raised from frons in male ; frons with sharp close punctures 

 and a pointed tubercle just above interantennal process; wider 

 flagellar segments about 1.8 to 2.1 as wide as long; second segment of 

 maxilla apically somewhat enlarged in male, apically globular in 

 female; punctures on mesopleurum large, separated by about 0.7 

 their diameter; first tergite in profile about 1.7 as long as high, weakly 

 rounded above; third and fourth tergites with a median carina; 

 third to fifth tergites with strong oblique grooves in their lateral 

 faces; apex of sixth tergite of male simple, of female deflexed medially 

 to make a broad, weak, median emargination. 



There are four subspecies, as treated below. 



