Collections of the Academy. 27 



three feet in diameter. Turritellites had an open coil 

 rising to a point in the center, while the Baculites were 

 straight, chambered shells. These are all represented 

 in our collections. Trees such as we now have first grew 

 in abundance during the Cretaceous period. Their leaves 

 are preserved in the rocks of that time, and we have 

 many specimens of them. 



Coming down to more recent times, the yesterday 

 of geology, this part of our country had wild elephants 

 living here. Their remains are frequently found from 

 Alaska to Florida. We have a lot of the bones of these 

 monsters in our collection. They were not Just like our 

 living elephants, but resembled them in form. They 

 were frequently much larger, and the one, the remains 

 of which we have, was not less than ten or eleven feet 

 in height. These bones, for they are so recent that they 

 are still bones and not petrifactions, were found in Ne- 

 braska. One of the leg bones which we have is four 

 feet and eight inches in length. The vertebrae are eight 

 inches in diameter and four inches in thickness. The ball 

 and socket ones of the hip joint are eight inches in diam- 

 eter, while those of an adult man are only about one and 

 one-quarter inches in diameter, thus showing the im- 

 mense difference in bulk between man and the mammoth. 



When the white men first came to this part of our 

 country they found it peopled with a warlike nation of 

 Indians called the Sioux. But long before then there had 

 been another Indian people called Mandans, who had oc- 

 cupied this region for a long time. The Indian mounds, 

 which are so numerous all over the northwest part of our 

 state, were probably constructed by these Mandans or 

 even an earlier race of Indians. These mounds are full 

 of broken pottery, flint, bone and shell implements. 

 From a large mound near our city thousands of such 

 si)ecimens of Indian work have been taken, and many 

 more thousands are yet buried there. Our collection 

 contains many of these relics of a people who long ago 

 disappeared from this part of the country. We have also 

 a cast from the largest stone ax ever found in the U. S. 

 Its dimensions are fourteen inches in length, eight inches 

 in width and three and one-half inches in thickness. The 

 weight of the original is 31 pounds. This original was 



