50 The Hawkeye Ornithologist and Oologist. 



sized molar of the Brontotheriurn . 

 There are eight or nine molars up- 

 on each side of the upper jaw. The 

 back molar is 3 to 3J inches square 

 upon the crown, and each one from 

 back to front of mouth issmaller in a 

 graduating scale until a conical-shap- 

 ed tooth, a sort of a tusk, is reached. 

 The teeth are great, handsome and 

 most wonderful specimens, with per- 

 fectly preserved enamel. The skull 

 of this animal at full size is about 

 three feet long and twenty inches 

 "wide. The concaved curved maxi- 

 lary bone bore two great horns. The 

 animal is said to have attained a 

 length of 28 feet and aheightof 9 feet. 



The second cut is an inferior one 

 and imperfectly represents the tooth, 

 perhaps of the same animal. . The 

 lower jaw containing this form of 

 tooth and the upper jaw containing 

 the former tooth have been found 

 paired together in one complete head. 

 Set., we call the former Brontothe- 

 rium and the latter Titanotherium 

 both belonging to the family called 

 Brontotheridae. 



The "Titanptherhim" back molar 

 has three crests and is 4| to 5 inches 

 long by 2 inches wide, .and-' the" nest 

 tooth towards the front has but two 

 crests. The outer edge of these 

 crests of both species are sharp cut- 

 ting edges, the inner points are 

 rounded. 



The third cut here shown repre- .. 

 sents a skull and upper teeth of an . 

 Oreodon Gracilis. These teeth are 

 keen, sharp, jagged cutters, and ap- , 

 pear as having three rows of crests. 

 They are very interesting specimens. , 

 The head and body are about the 

 size of a dog. We obtain some heads, 

 showing all the teeth in places in up- • 

 per and lower jaws clashed together, 

 excepting the front incisors. 



The Miohippus, or three toed 

 horse, is found here. The teeth are 

 unlike those of any other animal disr 

 covered, and cannot be clearly des- 

 cribed here. They must be seen: to- 

 be appreciated. The animal had 

 three divisions to each foot and, a. 

 small hoof to each division, and- is 

 said to be one of the developing prpr 

 genitors of our modern horse. 



The Hyracodon (a tertiary, Rhinpc- 

 erous)teetli found are nearly square 

 with zigzag edges on the crown. 

 They are about f- inches square, gen- 

 erally. The Phenocodus teeth, are 

 rarely fqjind. These have fovy 

 rounded ' tubercles ■ interior . ,tp the 

 surface of the ' crown thati J ,,gjve the 

 teeth" a very ^handsome' appearance; .. 

 The remains of' the Mastodon ... (an 

 Elephant) Beaver, Wolf, Tapir, etc., 

 are also found in this wonderful re- 

 gion. 



