294 PROCEEDINGS -OF THE ACADEMY OF "1883. 



THE OCCIDENT ANT IN DAKOTA. 

 By Rev. II. C. McCook, D. D. 



I have recently received from Prof. J. E. Todd (Professor of 

 Natural Sciences at Tabor College, Iowa, and an Assistant on the 

 U. S. Geological Survey), some A-aluable facts concerning the 

 distribution of Pogonomyrmex occidentalis. While on a visit to 

 Dakota (1882), Prof. Todd had observed a number of ant-hills 

 which awakened his interest, and upon which he made various 

 observations. The facts noted, together with specimens of the 

 insects and scrapings from the mounds, were sent to me, and 

 justify the following record : — 



1. Distribution and Site. — The ants were seen (A. D. 1882 and 

 1883) on the Missouri River, south of Bismarck, opposite the 

 mouili of the Cannon Ball River, and at a point sevent3--five 

 miles southward. Upon the extensive plain forming the bottom 

 of theBois Cache Cieek va]le3',and near the sand hills and grove 

 which give the name to the valley, tlie mounds are numerous. 

 Prof. Todd thinks with some confidence that they are not located 

 in the valley of the James River, nor in Dakota, an}' considerable 

 distance east from the Missouri River. He has traveled with a 

 team over 2500 miles in Dakota, east of the Missouri River and 

 south of the Northern Pacific Railroad, and has not noticed 

 the ant-hills elsewhere than the localities mentioned. In my 

 book on "The Honey and Occident Ants,"' I have located this 

 ant in southern Dakota, upon conjecture, but the above, with 

 specimens, now give scientific confirmation. 



I wish to call attention to the additional facts thus con- 

 tributed in the precise line of the striking feature formerly 

 pointed out by me in the geographical distribution of Occi- 

 dentalis. According to Prof. Todd, the r.nt is confined to the 

 bottom lands along the Missouri, and has not j^nshed eastward 

 through the Territor3% This corresponds remarkably' with my 

 conclusion, both from ni}* own observations and those made under 

 m}'^ direction by Dr. Horace Griffith, of Marengo, Iowa. This 

 conclusion is that Occidentalis does not dwell east of the Missouri 



^ The Honey Ants and the Occident Ants, p. 124 5. J. B. Lippincott & 

 Co., Phila. 



