THE DEVELOPMENT OF SCAPHITES 



W. D. SMITH 

 Manila, Philippine Islands 



CONTENTS 



Introduction. 



Description of Species. 



Distribution. 



Ontogeny and Phylogeny. 



Acceleration and Degeneration. 



Variation. 



Conclusion. 



Bibliography. 



INTRODUCTION 



The material used in this study is that of the Paleontological 

 Collection of Leland Stanford Junior University, and includes 

 material collected from two very different localities. 



In 1900 Mr. Milnor Roberts collected, in the vicinity of Sand 

 Springs, thirty miles north of Wibaux, Mont., a suite of fossils, the 

 majority of which were Scaphites. The rock is a dark, very hard 

 and compact limestone, and contains the following genera and 

 species : 



Scaphites nodosus 

 Scaphites nodosus var. brevis 

 Scaphites nodosus var. plenus 

 Scaphites nodosus var. quadrangular is 

 Scaph ites mullan anus 



With these occurred: 



Nautilus dekayi Bacidites ovatus 



Inoceramus barabini Pyrajsus (Neplunella) subturritus 



Inoceramus sagensis Protocardia salinaensis ( ?) 



Ant alls Protocardia rara 



Volsella meekii Necera ventricosa 



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