SOME DINOSAURIAST REMAINS. 



699 



Of the taxonomic position of Ornithopsis in the Order Dinosauria 

 there cannot be any doubt. Accepting Prof. 0. C. Marsh's classifi- 

 cation as best representing* our present knowledge of the order, Orni- 

 thopsis certainly falls into the group Sauropoda, and should find its 

 place amongst the members of the Atlantosauridse. 



Part II. 

 Omosatjrus. 



The remains which in May 1886 were thought by Dr. Wood- 

 ward and myself to be referable to Omosaurus, a Dinosaurian genus 

 of which the type specimen, from the Kimmeridge Clay of Swindon, 

 is preserved in the British Museum, comprise a sacrum with 

 both ilia, a caudal vertebra, parts of the other vertebral centra, a 

 femur, a metapodial bone, and many small and indeterminable 

 fragments. 



Pelvis. — The sacrum, still retaining its connexion with the ilia, 

 is mutilated, and it has been flattened and otherwise disturbed by 



Fig. 2. — Pelvis of Omosaurus durobrivensis, Hulke, from the Kim- 

 meridge Clay of Northamptonshire. One-tenth natural size. 



pressure, which has overthrown and squeezed down the spinous pro- 

 cesses upon the right transverse processes, hiding the junction of these 

 with the neural arches. The centra of the vertebras have disappeared, 

 so that in a ventral view the under or neural surface of the neural 

 arches is seen. The arches appear synostosed, thus forming a 

 continuous vault in which the original distinctness of its several 

 segments is doubtfully traceable, a structural arrangement architect- 



3b 2 



