Exhibition of Extinct Vertebrates 99 



Work was continued upon the carnivorous dinosaur collec- 

 tions from Alberta, especially upon the skeleton of the gigantic 

 Gorgosaurus mounted in a running pose, and 

 Preparation now nearly ready for exhibition. This skeleton 

 Exhibition * s a P ane l mount, but set up in sections instead 

 of a single piece. It will be temporarily installed 

 in the fossil mammal hall, as space is not now available with 

 the Cretaceous Dinosaur exhibits where it naturally belongs. 

 Three fine skulls of carnivorous dinosaurs from Alberta were 

 completed and placed on exhibition, and considerable progress 

 was made in the preparation of the slender-limbed Ostrich 

 Dinosaurs and their allies, a rare and little known group of 

 which a number of partial skeletons remain to be prepared, 

 in addition to the complete skeleton on exhibition. Two partial 

 skeletons of a primitive type of Duck-billed Dinosaur were 

 finished up and placed on exhibition. 



A model of the great Amphibious Dinosaur Camarasaurus, 

 completed by Erwin Christman in accord with the latest 

 researches by Professor Osborn, Dr. Gregory and Dr. Mook 

 on the pose and habits of these animals, was cast and placed 

 on exhibition at the entrance to the Dinosaur hall. This model, 

 representing a very detailed study, is believed to be the most 

 authoritative reconstruction yet made of an amphibious dino- 

 saur. 



About a third of the time of the laboratory staff was devoted 

 to the exhibits and study collections of fossil Proboscidea. The 

 skull of the great Long- jawed Mastodon was partly recon- 

 structed in conformity with later comparative studies; and 

 the palate and jaws of another species, T. campester, were 

 very carefully and critically reconstructed and restored. A 

 very fine and complete skull and jaws from the Lower Pliocene 

 of Texas was placed on exhibition, and a number of changes 

 made in the panel exhibits of fossil proboscideans. Some prog- 

 ress was made towards the completion of the Primitive Mas- 

 todon Skeleton (Trilophodon protluctus) . 



Preparation of the large block of Diceratherium (dwarf 

 rhinoceros) from the Agate fossil quarry has been nearly com- 

 pleted. This block contains twenty-one skulls, and a propor- 

 tionate number of skeleton bones (reckoning 180 bones to each 



