AllanI — The Stridulations of some " Katydids.'" 39 



response to others in the trees out-of-doors. The notes which 

 show considerable variation in length and intensity are sharp, 

 snapping crepitations, and sound much like the slow snapping 

 of tlie teeth of a stiff comb as some object is slowly drawn 

 across it. They may be more or less accurately expressed 

 thus: tek-ek-ek-ek-ek-ek-ek-ek-ek-ek-ek-tzip — tek-ek-ek-ek-ek- 

 ek-ek-ek-ek-tzip. The first notes are very distinct and incisive, 

 but grow fainter with a rapid decrease in the intervals separat- 

 ing each single syllable, — ek-ek, and terminate with a single, 

 loud, rasping tzip. In some instances this tzip is followed l)y 

 a succession of several barely audible clicks of the wings, tek- 

 ek-ek-ek-ek-ek-ek-tzip-ek-ek-ek-ek. After dark on warm, sum- 

 mer evenings this katydid is a very persistent singer. Riley 

 describes the notes of Microccntrum rhombifulium very accurately. 

 He says: "The song consists of a series of from 25-30 rasp- 

 ings, as of a stiff quill drawn across a coarse file. There are 

 about five of these raspings or trills per second, all alike and 

 with equal intervals, except the last two or three, which, with 

 the closing of the wings, run into each other. The whole 

 strongly recalls the slow tvirning of a child's wooden rattle, 

 ending with a sudden jerk of the same . . . . " 



The true katydid CyrtopJn/Uvs perspicillatus Linnauis is also 

 strictl}^ an arboreal species. Its stridulations, which rarely 

 begin before dusk, are prol)abl3' the hardest and most rasping 

 notes produced by any of the LocustidtB. At Thompson's 

 Mills, Georgia, it is a very common species, and noisy colonies 

 occupy nearly every wooded tract. In the evolution of this 

 species, the power of sustained flight has been quite lost, so 

 that when disturbed in its leafy hiding place among the top- 

 most branches of the forest trees, it drops to a lower limb or 

 sails gently to the ground. Cyrtophylhis perspicillatus is very 

 sedentary in its halnts, and shows little disposition to migrate, 

 in part owing to its limited powers of flight. I have frequently 

 noted that the same individual may occujiy a certain tree or 

 liml) throughout the summer. This katydid is evidently gen- 

 erally distributed throughout the hill and mountain section of 

 north Georgia, for even in the forests on Tray and Blue Moun- 

 tains, Towns County, I heard their stridulations in late 

 September. 



The notes of this katydid are sharp, emphatic rasping sylla- 



