244 FAMILY VI.— LOCUSTID^. 



The females are evirlently handicapped in their leaping pow- 

 ers by the excessive length of the ovipositor, and so more 

 often endeavor to escape by burrowing beneath the dense 

 masses of fallen grass and reed-stems which are always 

 found in their accustomed haunts." 



He also finds that the length of the ovipositor among 

 the different species of Xiphidium is not at all dependent 

 upon the age of the insect. In attenuatum it is almost as 

 long after the third, and fully as long after the fourth molt 

 as it is in the imago. 



The eggs oi attenuatum, as the length of the ovipositor 

 indicates, are laid between the stems and leaves of tall 

 grasses. 



The sub-family Decticinas contains a large number of 

 genera, of which only two occur in Minnesota, and very 

 sparingly at that. 

 a. Prosternum armed with two erect spines. Large but 



not bulky insects Atlanticus. 



aa. Prosternum unarmed. Large and very bulky insects. 



Anabrus. 



GENUS Atlanticus Scuddcr. 



Head rounded; face broad, but slightly oblique; vertex 

 compressed, with a blunt, decurved projection between the 

 antennae, which is slightly excavated on thesides; pronotum 

 flattened on top with the lateral carinee sharp and abruptW 

 bent down at the sides. The pronotum is narrower in front 

 than behind, and slightly pinched before the middle; it also 

 extends backwards over the first abdominal segment. Wing- 

 covers of the female rudimentary and hidden under the pro- 

 notum; those of the male about half as long as the body; 

 ovipositor stout at base, straight, flattened, and pointed 

 obliquely upwards; as long as the body. The shrilling 

 organ, which is covered by the pronotum, is circular, and 

 rather larjje for the size of the tegmina. 



