37^ " NEW YORK STATE MUSEUM 



PLATE 10 



Piloceras explanator Whitfield 



A nearly complete siphuncle showing above a cast of the endosi- 

 phocone covered by the last endosiphosheath [see pi. 13, fig.i] and 

 below the exterior of the siphuncle with the very obliquely passing 

 fracture lines of the septa along their flexures in the endosiphuncle. 

 The numbers correspond to the sections made through this siphuncle 

 and reproduced on plate 11. Natural size 



The original from the Beekmantown beds at Fort Cassin Vt. 

 (collected by C. Rominger 1888) 



