12 ORTHOPTERA OF NORTHEASTERN AMERICA. 



diana and Virginia, has furnished me numerous specimens and 

 has contributed a manuscript list of the species taken near Clarks- 

 ville, Tenu. T. H. Hubbell of the University Museum of Zoology 

 at Ann Arbor, Mich., prepared for me a similar list of Michigan 

 species and kindly loaned specimens for examination. Others 

 who contributed distribution data, specimens or other helpful aid 

 were the late Chas. A. Hart of Urbana, 111. ; Win. J. Gerhard of 

 the Field Museum, Chicago ; Prof. J. R. Watson, Dr. E. H. Berger 

 and P. W. Fattig of Gainesville, Fla, ; H. P. Loding of Mobile, 

 Ala. ; Prof. H. Garman of Lexington, Ky. ; Nathan Banks of Cam- 

 bridge, Mass.; Dr. Win. A. Riley of the University of Minnesota; 

 Myron H. Swenk of Lincoln, Neb. ; J. R. Malloch of Urbana, 111., 

 and Chas. A. Dury of Cincinnati, Ohio. 



It is a pleasure to acknowledge and extend thanks to all the 

 parties above mentioned, for, situated as I have been far from any 

 large collection or reference library, the work in its present form 

 would not have been possible had it not been for the aid so freely 

 given. 



RELATION OF AN ORTHOPTERON TO OTHER ANIMALS. 



If we compare the body of a locust or other insect with that of 

 any vertebrate animal, as a fish, bird or squirrel, we find at once 

 great and important differences. The vertebrate is an animal 

 with an inner bony skeleton, two pairs of jointed limbs or append- 

 ages, and breathes by means of lungs or gills, according as it 

 dwells in air or water. The locust is an animal which has no 

 inner skeleton or bones whatever, but only a hard crust on the 

 surface which surrounds the muscles and vital organs. This crust 

 is composed of separate rings, placed end to end. 



Animals whose bodies are thus composed of rings are called 

 Articttlata. They are in turn divided into two great groups, the 

 Vermes and the Artliropofln. The Venues (worms) have all the 

 rings composing the body very nearly alike, not hardened into an 

 outer crust or exoskeleton, and without paired limbs which are 

 jointed. The Arthropods have a part of the rings bearing paired 

 jointed appendages, and have the cuticle or outer surface consist- 

 ing largely of a peculiar substance called "chitin," which is secret- 

 ed or exuded by the cells which compose the cuticle. Chitin itself 

 is insoluble and is not composed of cells, but consists of fine, irreg- 

 ular plates. It hardens the cuticle and thus aids the latter in pro- 

 tecting delicate vital organs within, and also in forming a frame- 

 work to which the muscles of movement mav be attached. Between 



