AKT.16. SOME PECULIAE FOSSIL FORMS MANSFIELD Q 



Plate 5 



Fig. 1. Small, elongate, nearly cylindrical form associated with Xenohelix 

 marylandica at the type locality. Cat. No. 354139, U.S.N.M. 

 Slightly reduced. 

 2, 8. Fragment of nearly straight and cylindrical form taken from the upper 

 part of bed No. 1 of section 3 (p. 2) of the St. Marys formation, 

 about one-third mile below the site of the old Langley homestead 

 Cat. No. 354141, U.S.N.M. Slightly reduced. 



2. Upright position of specimen. 



3. Cross section of larger end of same specimen showing thick peripheral 



wall and central core. 



o 



