MARYLAND GEOLOGICAL SURVEY 137 



This form is very rare. Perhaps it should be called a variety of 

 C. conulus, to which it is most nearly related. 



Length, 4 mm. ; diameter, 2.5 mm. 



Occurrence. — Calvert Formation". Plum Point. 



Collections. — Maryland Geological Survey, Cornell University, Phila- 

 delphia Academy of Natural Sciences, U. S. National Museum. 



Family SCAPHANDRIDAE. 



Genus CYLICHNA Loven. 

 CyLICHNA ( ?) GREENSBOROENSIS n. Sp. 



Plate XXXIX, Fig. 13. 



Description. — Small, slender, tapering anteriorly, surface everywhere 

 non-cylindrical ; sculpture absent ; mouth widest below. 



There is a specimen in the National Museum from Plum Point which 

 apparently belongs to this species. 



Length, 3.5 nun.; diameter, 1.5 mm. 



Occurrence. — Choptank Formation. Greensboro. Calvert For- 

 mation (?). Plum Point (?). 



Collections. — Maryland Geological Survey, U. S. National Museum. 



Cylichna calvertensis n. sp. 

 Plate XXXIX, Figs. 14, 15. 



Description. — Shell small, cylindrical, without sculpture; spire hid- 

 den; spiral end nearly flat; proportional length variable. 



Length, 3 mm.; diameter, 1.3 to 1.5 mm. 



Occurrence. — Calvert Formation. Plum Point. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 Cornell Universitv, U. S. National Museum. 



