TABLE OF CONTENTS. 
PAGE 
Preface 5 
Introduction 7 
Original Descriptions 7 
Barosaurus lentus Marsh 7 
Barosaurus affinis Marsh 8 
Locality and Horizon 8 
Matrix and Inferred Habitat '8 
Material 10 
Morphology of Barosaurus lentus 1 
Axial Skeleton 1 
Skull 1 
Cervical Vertebrae 1 
Cervical XII 1 
Cervical XIII 13 
Cervical XIV 14 
Cervical XV 14 
Dorsal Vertebrae 15 
Dorsal I 15 
Dorsal IV 16 
Dorsal V 18 
Dorsal VI 19 
Dorsal VII 19 
Dorsal IX 20 
Dorsal X 21 
Sacrum 22 
Caudal Vertebrae 22 
Caudal II 22 
Caudal III 23 
Caudal IV , 24 
Caudal V 25 
Caudal VI 25 
Caudal XIII 25 
Caudal XV 27 
Caudal XVI 27 
Caudal XVII 27 
Caudal XIX 28 
Caudal XX 28 
Caudal ca. XXXII 29 
Caudal ? 29 
