2 TETTIGID.^ OF NORTH AMERICA 



figures were made by the author and with but few exceptions, 

 designated further on, are taken from nature. 



After the description of each species the bibliography is 

 appended. This part of the work was facilitated by the recent 

 appearance of the excellent " Index of North American Orthop- 

 tera," by Dr. S. H. Scudder. New synoptical tables are pre- 

 sented herewith, which modify to some extent those already 

 published by the author. In the biological field there are 

 many problems here suggested which invite the student of 

 evolution. For instance, of peculiar interest is the last ecdy- 

 sis in which the elytra in many of the northern forms, which 

 in the earlier larval stages are obscured from view, now take 

 a position at the side of the body in the posterior elytral 

 sinus. The wings likewise become explicate, taking a folded 

 position when at rest under the pronotum, where they become 

 partly visible. Few groups of insects present such numerous 

 variations, which, viewed from the quantitative standpoint, are 

 as yet but little appreciated. Again, the embryology of the 

 group will doubtless throw important light on very interesting 

 questions of its phylogeny. 



It would have been impossible to present the subject, even 

 in its present form, without the kind co-operation of a number 

 of observers who generously aided me in various ways. To 

 them the author here takes pleasure in acknowledging his 

 obligation.* Professor Ignacio Bolivar, of Madrid, Spain, 

 identified some of the doubtful species referred to him, and 

 very generously furnished a number of exotic forms. Mr. 

 A. P. Morse, of Wellesley, Massachusetts, in a like spirit 

 of generosity, allowed me to examine a large series, and 

 contributed a number of species to my collection. Some of 

 his types were also examined. Dr. S. H. Scudder, through 

 whose correspondence a number of species have been clearly 

 defined, allowed me the opportunity of examining his type 

 examples of Tcttix acadiciis and Paxilla obesa. To Professor 

 H. De Saussure the author is indebted for a rare copy of one 

 of his memoirs and correspondence. From Mr. Malcolm Burr, 



• I am much indebted to the officers of the United States National Museum for placing 

 the collection comprising three hundred and thirty-two specimens at my disposal for 

 study. 



