172 



HYMENOPTERA. 



above, than in the other genera ; the front of the head is about 



a third longer than broad. The antennjie are long and fili- 

 form and sometimes crenulate, as in Figure 91a, in the 

 males ; the mandibles are stout, broad, sabre-shaped, 

 being much curved, with low llattened teeth, and the 

 maxillary palpi are longer than the labial palpi. The 

 wings are rather broad, with the three subcostal cells 

 Ij'ing in a straight row. The abdomen is slightly com- 

 pressed, and equals in length the remainder of the 

 body. The sting is very large and formidable, and ex- 

 cessively painful, benumbing the parts it enters. They 

 are exceedingly active, running and flying over sandy 



places like winged spiders. 



There are about five hundred species of this genus described.- 



They are usually shining black or deep bluish black, with 



Fig. ill rt. 



Fig. 92. 



smoky or reddish wings, and sometimes a reddish abdominal 

 band. This genus is interesting, as affording in its form a 

 mean between the globular thorax and short body of the 

 ApiarifB and the elongated body of the Ichneumonidce. 



The Pompilus formosus Say (Fig. 92), called in Texas the 

 Tarantula-killer, attacks that innnense spider the Myr/ale Hciitzii, 

 and, according to Dr. G. Lincecum (American Naturalist, May, 



