SUBFAMILY V. DECTICIN.E. 



601 



This interesting Decticid has been taken on several occasions 

 by E. M. Walker at Ft. William, Out., where it was first found in 

 rather long grass. He records it also (1901), 210) from A \veme, 

 Man., and Millarville and Calgary, Alta. Candell informs me 

 that his Idionotus brcripcs (1007, 390) from "Arctic America" is 



Fig. 199. Idionotus spliagnornm (F. Walker.) a, Male, X 2- (After E. M. Walker.) 

 b, Female, X i-3- (After Caudell.) 



the male, and his Platycleis f letch cri (1907, 403) the female, of 

 / spJidf/iiormn. The known range of the species extends from 

 northwestern Ontario to western Alberta and northward to Arctic 

 America, F. Walker's types being from St. Martin's Falls, Hud- 

 son's Bay. 



Of the habits of /. spliaynorutn, as noted at Ft. William, E. M. 

 Walker (1911) says: 



"In addition to open grassy places it occurs also in paths and old lum- 

 ber roads in the depths of spruce swamps. The tree growth in these 

 swamps consists mainly of black spruce, interspersed with tamarack, white 

 cedar and balsam fir. With the exception of a single female, which I found 

 squatting close to the ground on a path in the swamp, all the specimens 

 taken were males, and were all traced by their stridulation. When dis- 

 covered, they were sometimes found perching in a conspicuous position 

 upon the upper side of a leaf or twig of some shrub, a few feet from the 

 ground, but several times the sound was traced to the trunk of a tree, and 

 the musician was in some cases too high up to be detected. 



"The stridulation of this grasshopper is a soft trill of little volume, 

 audible at a distance of but a few yards. It is sometimes continuous for 

 some seconds, but is generally interrupted rythmically, the divisions being 

 produced at a rate varying according to the amount of sunshine. In bright 

 sunshine I counted forty in fifteen seconds, the rate being thus two and 

 two-thirds divisions per second, but on an afternoon when the sun was 

 almost wholly overcast the rate was reduced to forty-one or forty-two in 

 thirty seconds, or about half the rate in sunshine. When close to the strid- 



