14 BUIXBTIN 27 134 



at first but with a few ribs on the later portion ; post -nuclear 

 whorls 5 ; the body- whorl with 15 straight, low ribs ; spiral 

 sculpture of irregular bands ; 1st post -nuclear, whorl with 6 e- 

 qual spirals ; the other spire-whorls have generally 5 heavy and 

 6 fine spirals ; the body- whorl with about 21 spirals, strongest 

 on the middle of the whorl ; bordering the suture, there are 6 

 small, closely crowded spirals ; a small sulcus encircles the base, 

 covered with spirals ; mouth ovate, angulated above ; outer 

 lip thickened and denticulated within ; inner lip callused and 

 with a few denticles below ; siphonal fasciole strong. 



Length 11 , breadth 6, body -whorl 6 mm. 

 This species is readily recognized by its large body- whorl, 

 pointed spire, and unequal, spiral bands. In general characters, 

 the species approaches N. consensu Ravenel but is sufficiently- 

 distinct for recognition and is the Miocene precursor of that 

 species. 



Duplin formation ; Natural Well, N. C. 



Nassa shack lefordensis, n. sp. Plate 2, Fig. 4 



Shell small, coronate, sculptured with straight ribs and few, 

 raised spirals ; nucleus of 3 small, smooth whorls ; post-nuclear 

 whorls 4, shouldered above and with the area bordering the su- 

 ture with the ends of the ribs, with or without a spiral ; on the 

 spire-whorl, there are 3 or 4 narrow, raised spirals which cross 

 both the riblets and the spaces between ; the riblets are some- 

 what granulated by the spirals ; interspaces between the spirals 

 very wide; on the body- whorl, there are 3 or 4 additional spi- 

 rals on the base ; body -whorl with 14 narrow, straight riblets 

 with wide spaces between ; mouth rounded, smooth or faintly 

 lirate within ; canal short, straight. 



Length 6, breadth 3 mm. 

 This species in most of its characters is a diminuative JV. 

 trivittata. The resemblance is due to the coronate character of 

 the whorl , straight ribs and sharp spirals. Typical N. trivittata 

 is not known from our east coast Miocene. 



Miocene; Shakleford, Va. 



