1 24 THE A ME RICA N M USE UM JO URN A L 



other bones were collected for the Museum, and these are but a 

 small fraction of the entire number in the fissure. More than 

 sixty different species of mammals, birds and reptiles, chiefly of 

 a forest fauna, have been recognized, some of which still live in 

 the same region. Many others now inhabit near and remote 

 northern parts of the continent, while twenty-four species are 

 entirely extinct. The fissure has thus given us a record of some of 

 the kinds of animals in Arkansas at the time of the most southern 

 extent of the great ice-sheet of the Glacial Period. A systematic 

 series illustrating the different species found in this interesting 

 fissure is in process of installation in a case which has been placed 

 temporarily in the Dinosaur Hall. 



THE SHETLAND PONY SKELETON. 



HE series of specimens in the Horse Alcove of the 

 Hall of Vertebrate Palaeontology has been enriched 

 by a beautiful skeleton of an adult Shetland pony, 

 which was prepared and mounted. at the Museum 

 by Mr. S. H. Chubb. The skeleton represents 

 the animal as if grazing, w^hich admits the display of great skill 

 in the adaptation of the bones to the necessities of the case. The 

 downward reach of the head causes the backbone to be con- 

 siderably arched, and this necessitates raising the angle of the 

 pelvis several degrees toward the vertical, increasing the length 

 of the hind limbs and tilting the body forward. The head is 

 turned to the right, producing interesting curves in the back- 

 bone. The attitude of all the bones has been determined from 

 a most careful study of photographs of the animal while alive. 

 An examination of the skeleton shows that the weight of the 

 body falls on the right front and the left hind foot, bringing them 

 both very near the median line, modifying the position of the 

 scapulsE' and elevating the left side of the pelvis. 



The skeleton of the Shetland pony has been placed beside 

 that of the great Percheron draft horse, marking the extremes 

 of development produced by artificial selection. The contrast 

 between the two animals is well shown in the following table of 

 measurements : 



