1 6 Bulletin 27 136 



the Department of Geology of Cornell University. 



Yorktown formation ; Kingsmill, Va, ( type locality ) 

 Grove Wharf, Va. 



Scalalineata Say, var. magnoliana, n. var., Plate 1, Fig. 5 



Shell moderately large, elongate, with 6 + whorls ; whorls 

 rounded, with the suture distinct but not deep ; varices small 

 and irregular, numbering on the body-whorl about 13 ; on the 

 base of the last whorl there is an elevated area well-defined by a 

 ridge above ; intervarical spaces with irregular spiral bands, 

 generally those situated on the periphery the strongest ; mouth 

 rounded with a very thick varix at maturity. 

 Length 14.5, breadth 6.5 mm. 



This shell may prove to be distinct from the recent 5". lin- 

 eata Say. The exceedingly heavy lip at maturity is most cha- 

 racteristic. 



Dupii?i formation ; Natural Well, N. C. 



CERITHIOPSIS Forbes andHanley 

 Heterocerithiopsis, n. subg. 



Protoconch of — whorls ; the last nuclear whorl is strong- 

 ly angulated in the middle, with a resulting sharp periphery ; 

 above the periphery with numerous, curved, smooth riblets, be- 

 low, with two sets of riblets, which pass obliquely and intersect 

 each other at nearly right angles, thereby producing rows of 

 squarish pits ; change to the post-nuclear whorls abrupt. 



Type, Cerithiopsis smithfieldensis, n. sp. 



Cerithiopsis smithfieldensis, n. sp., Plate 1, Fig. 7 



Shell small, elongate-conic, with slightly convex outlines ; 

 protoconch of 1 + whorls (the tip broken on my specimens ) ; 

 the last nuclear whorl strongly keeled ; above the peripheral 

 keel with 20 curved, oblique riblets, below with oblique riblets 



