Report of the President 35 



extinct marine reptiles of Europe which have been acquired 

 chiefly through exchange and gift. 



The most important additions to the exhibition series are 

 the skeletons of Cryptodidus, a Plesiosaur or marine reptile of 

 the Jurassic Period, and of Camptosaurus, an American relative 

 of the Iguanodon of Europe; a fine skull and jaws of the great 

 Horned Dinosaur, Triceratops, and a skull of Mastodon. A num- 

 ber of important skeletons or groups are ready for exhibition or 

 are in course of preparation. Of these the group of four great 

 Ground Sloth skeletons (completed) and skeletons of a small 

 ancestral Ground Sloth and of the peculiar extinct Ungulates, 

 Toxodon and Macrauchenia (in preparation) are designed for 

 the South American exhibit in the new hall soon to be occu- 

 pied. A skeleton of the clawed ruminant, Agriochoerus, and a 

 panel mount of five skeletons of Stenomylus, an extinct Came- 

 loid, have been completed for the Fossil Mammal Hall. For 

 the Dinosaur Hall the skeleton of the Toothed Bird, Hesperor- 

 m's, and the " Dinosaur Mummy " are completed; those of the 

 primitive reptile, Diadectes, and the primitive amphibian, Eryops, 

 of the Permian Period, are nearly completed ; the Tyrannosaurus 

 group, two giant carnivorous dinosaurs with their prey, is well 

 under way, and work has begun on a mountable skeleton of the 

 Horned Dinosaur, Triceratops. 



In all the more important recent exhibits of this department 

 the object has been, by grouping and selection of characteristic 

 poses and by adding suitable accessories, to increase their in- 

 terest and teaching value. This method, widely adopted for 

 exhibits in recent zoology, appears to be equally successful in 

 the exhibition of fossil vertebrates. With collections of the 

 size that those of this department have attained, it appears im- 

 portant to aim at quality rather than quantity in its exhibits and 

 to show a few impressive and instructive groups rather 

 than a much larger number and variety of individual 

 specimens. 



A series of four large wall panels for the Tertiary Mammal 

 Hall, the gift of Mr. J. P. Morgan, Jr., illustrating faunal 

 life scenes in that period, has been designed and the pre- 

 liminary drawings completed by Mr. Knight, under direction 

 of Professor Osborn. 



