Plate XIII. 



Radiolites diividsoni sp. nov. 



Tlie illustrations show an elongated specimen with details of its general 

 structure. In the lower right-hand corner is a figure showing the two 

 main sutures, which extend the entire length of the shell, but are not 

 seen in" the large illustration. Jnthe lower left-hand corner is an end 

 view of the specimen figured. The object in the upjjer right-hand por- 

 tion of this figure is a fragment of the broken upi^er valve. 



