168 



Maine Agricultural Experiment Station. 1917. 



P. guadratus Say. 



Front tibia on the inner side 

 slightly but distinctly concave. 



P. perpallidus Verrall. 



Front tibia on the inner side hard- 

 ly at all concave or quite 

 straight. 



Middle femur with a cluster of 

 long dense pubescence at the 

 base. 



Middle femur entirely without a 

 basal cluster of pubescence. 



The tip of middle femur w^ith a 

 somewhat denser clump, of 

 slightly finer hairs. 



Middle tibia more flattened and 

 broader ; and the first segment 

 of the tarsus somewhat flat- 

 tened. 



The tip of middle femur with few- 

 er but heavier hairs. 



Middle tibia less flattened ■ and the 

 first segment of middle tarsus 

 entirely cylindrical. 



Last two joints of hind tarsus 

 black; the tip of the front tibia 

 behind is indefinitely infuscated, 

 the only black markings appear- 

 ing as three or four broken 

 transverse hair lines. 



Last two joints of hind tarsus 

 somewhat less blackened and 

 the tip of the front tibia behind 

 with a more distinct black spot. 



Abdomen with a distinct median 

 longitudinal black stripe .11 mm. 

 to .17 mm. wide ; i. e. roughly 

 one-tenth to one-twelfth the 

 Avidth of the segment thruout 

 segments two to four inclusive ; 

 and a distinct, posterior black 

 crossband of about equal width 

 on each of these segments, 

 Avhich occupies from one-sixth 

 to one-ninth the length of the 

 segment. 



Abdomen much less distinctly 

 marked with black; except the 

 first segment and a median an- 

 terior triangle on the second 

 segment, nearly pure orange yel- 

 low, the black mid-dorsal line on 

 segments two to four nearly or 

 entirely obsolete and the hind 

 jnargins of these segments very 

 narrowly and inconspicuously 

 black. The yellow abdomen 

 contrasts strikingly with the 

 brilliant black thorax in a man- 

 ner • suggestive of Pyrophacna 

 spp. 



The females, as in this entire genus, are distinguished with difficulty. 

 The specimens at hand have the median black line and the black crossbands 

 narrower than in guadratus, the abdominal markings more yellow and less 

 reddish fhan in guadratus and the fifth segment with the yellow not in- 

 terrupte 1 by the median black line and not excised with black behind. 



