137 Miocene Fossils, Olsson 



suture bordered by a thickened band simulating a raised spiral; 

 mouth short, with thickened outer lip and a deep anal notch. 



Length 14..5, breadth 5, body-whorl y , aperture 4.5mm. 

 This species differs from true bella by its larger size and in 

 the differences of its spirals which are low and more ribbon-like, 

 the spirals on bella being fine and well-raised. The species agrees 

 with bella in having the ribs extending up onto the contracted 

 subsutural zone, differing in this character as well as others from 

 Drilla belloides. 



Duplin formation ; Natural Well, N. C. 



Drillia smithfieldensis, n. sp., Plate 1, Fig. 6 



Shell elongate, with relatively small body-whorl and a well- 

 marked though shallow sutural zone; nucleus blunt of about 2 

 whorls, the first Yt, turn smooth, followed by a turn with 4 spirals, 

 of which the 3d from above is the strongest and carinates the 

 whorls; post-nuclear whorls 7, with short smooth-topped ribs and 

 with the spirals in the form of broad flat ribbons; the 1st post- 

 nuclear whorl has the contracted zone well-defined and sculptur- 

 ed with 2 flat spiral bands, below with ribs and 3 spirals; the 

 succeeding whorls show a gradual increase in the number of the 

 spirals but these remain low and do not cross the ribs; body- 

 whorl with 11 or 12 ribs, present only on the middle of the whorl 

 and leaving the base and canal sculptured only by the flat spirals; 

 spirals on the body- whorl about 9, fairly even above but irregu- 

 lar below; the 3d and 4th whorls have the edge of the suture 

 thickened, becoming on the succeeding whorls a wide raised 

 band ; mouth small, with a short canal, free from callus. 



Length 14..5, breadth 4.5, body -whorl 6.5 , aperture 4.. 5mm. 



This species is readily distinguished by its elongate shape 

 and short body- whorl. 



Yorktown formation; James river, north of Smithfield Va. 



