38 Alla7'd — The Strididat ions of some " Kati/dids." 



stridiilating near each other, the responses are likely to be 

 similar. If one singer begins its song witli the soft, silken, 

 continuous note, s-s-s-s-s-s-s-s-s, it is very quickly answered by 

 the other in precisely the same way. Tlie usual notes of 

 AmhUicorypha uhleri are, tip-sh-sh-sh-sh-sh-sh-sh, or this may 

 be preceded by several short notes, slowly delivered, tip-tip- 

 tip-tip-tip-tip — , sh-sh-sh-sh-sh-sh. The stridulations of this 

 katydid have evidently never been completely described, as 

 every part seems to be an essential love-call in its song. 



The katydids of the genus Microcentrurii are more strictly 

 arboreal than any of the preceding. Microrcntrnvi retlnerve 

 Burmeister is strictly an arboreal katydid, and dwells almost 

 exclusively in the crowns of the highest oaks, hickories, 

 maples and other deciduous trees. At Thompson's Mills, Ga., 

 this katydid, judging from the numbers stridulating during 

 warm, midsummer nights, is one of the commonest and most 

 noisy of all the Locustidas. Owing to its arboreal habits, how- 

 ever, it is not readily located and captured. Its notes, which 

 are loud, harsh and persistently delivered throughout the 

 summer nights, consists of several rapidly shuffled phrases, 

 each briefer than the last — sh-sh-sh-sh — sh-sh-sh — sb-sh — sh. 

 Wherever this katydid occurs, it is very locally distributed, so 

 that certain groves are almost without a singer. This katydid 

 is very common in the woods on Plummer's Island, Maryland, 

 above Washington, D. ('., but throughout the sunnner of 1909 

 I did not hear a single individual in the trees at Lincoln Park, 

 although Microcentrum rJiovd)ifoliiim was very common there. 



Microcentrum rhomhifol'mm Saussure is the largest and one of 

 the commonest katydids in much of the eastern United States. 

 At Thompson's Mills this s[)ecies is very common, and at 

 Washington, D. C, I find it perhaps the commonest katydid. 

 In the willows and small trees bordering the low grounds of 

 east Washington, it is a very common species, and the strident 

 calls of different individuals may be heard in m-arly every 

 bush. Although it is a rather shy species, with a little care it 

 may readily be taken, since it dwells in low shrubbery in open 

 situations, and is not a forest species. 



1 have carefully studied tlie peculiar stridulations of these 

 katydids by placing them on l)oughs in my room. Thi'oughout 

 the night tlieir crepitating notes were leisurely delivered in 



