SCUDDER. THE GENUS DEROTMEMA. 395 



similar to those, of lichen origin, upon the sage-brush. One could not 

 collect them without observing it. 



Both sexes of this grasshopper make a uoise in night. A male, 

 observed at Evanston and repeatedly followed and then captured, made 

 from six to twenty-four clicks in a uniform series at the rate of seventy- 

 two iu a minute, or six in five seconds ; a female at Alkali made a 

 succession of equidistant clicks, four or five to a second, in a short flight 

 in one direction, lasting only one or two seconds. These observations 

 were made, and most of the specimens collected, in 1877. 



Note. — Since this article was in type I have found that this last 

 species was described in 1871 by Thomas as Oedipoda gracilis. My 

 name will therefore fall. 



