ART. XXI -ON THE ORTHOPTERA COLLECTED BY DR. ELLIOTT 

 COUES, U, S. A., IN DAKOTA AND MONTANA, DURING 



1873-74.* 



By Prof. Cyrus Thomas. 



LETTER OF TRANSMITTAL. 



Caebondale, III., October 18, 1875. 



Sir : I transmit herewith a report on the collection of OrtlioiJiera sub- 

 mitted to me for examination. 



Although the collections are small, they are of considerable interest, 

 as adding to our knowledge of the distribution of species, some of which 

 find their northern limit in the region where your collections were made. 



The more we study the habits of Caloptenus spretiis, which is well rep- 

 resented in your collections, the more important does a thorough knowl- 

 edge of the western limit of your line of operatio ns become. Although 

 the entire Rocky Mountain region may be said to constitute the native 

 home of this locust, yet the region about the headwaters of the Missouri 

 appears to form a fertile source of the swarms which sweep east and 

 southeast upon the border States and the plains of Manitoba. As this 

 is a subject of great importance, and one in regard to which our national 

 government is no doubt anxious to gain all possible information, I have 

 added a somewhat lengthy note in regard to its operation. 



The list is comparatively small ; but it should be remembered that 

 Ortlwptera rapidly decrease in species as we penetrate into these north- 

 ern sections. Mr. Henry W. Elliot informed me that although he made a 

 careful examination he was unable to find a single specimen in the sec- 

 tion of Alaska in which he was stationed. Kirby's list, as you will see 

 by examining the '■'■Fauna BoreaU-Americana^\ is quite meagre. I find no 

 new species, at least none that I feel warranted in considering new, 

 although varying considerably from the types of the species to which 

 I have referred them. It is possible that the Gryllus which 1 have 

 referred to ahhreviatus is new; but before this can be determined, the 



[* These insects form part of the collections made by me as Surgeon and Naturalist 

 of the United States Northern Boundary Commission, Archibald Campbell, Esq., United 

 States Commissioner, Maj. William J. Twining, United States Engineers, Chief Astrono- 

 mer. They were all taken on or near the parallel of 49° N., along the northern 

 border of Dakota and Montana. 



The same remark applies to tha two next succeeding articles, by Mr. Uhler and" Mr. 



Edwards. — Ed.1 



481 



