OF NEW TERTIAEY FOSSILS. 113 



There is another species which occurs in fragments. It is small, rare, and is 

 smooth, polished and curved. 



FISSURELLA. 



F. MississippiENSis. PI. 11, fig. 2. — Suboval, rather elevated, with numerous unequal radiating lines, and 

 fine transverse lines, giving a minutely granulated appearance to the shell ; foramen oval, submedial. 

 Length i. Very rare. 



An echinated species occurs, apparently identical with I. trochiformis of Paris, and 

 of Claiborne, Alabama. 



SOLARIUM. 



S. TRiLiRATUM. PI. 11, fig. 4. — Discoldal, with three thick approximate ridges on the periphery; suture 

 channelled ; volutions with oblique impressed lines, and two fine revolving lines on each whorl ; base 

 convex, with three revolving impressed lines, that near the umbilicus profound, and with coarse rugose 

 transverse lines. Diameter 7-10. Not common. 



BULLA. 



B. CRASSiPLiCA. PI. 11. fig. 5. — Cylindrical, narrowing towards the base, smooth and entire; fold at 



base thick and prominent. Length 2-10. 



Abundant on Dr. Smith's plantation, six miles N. E. of Vicksburg. 



CYPRtEA. 



C. spH/ERoiDEs. PI. 11. fig. 6. — Short ovate, subgl obese ; posterior end narrow; base rounded ; aperture 



narrow, the margins with numerous teeth. Length li. 



Very rare. Mr. J. D. Anderson, of Vicksburg, found one, and I obtained only one 

 during the two weeks employed in collecting the fossils around Vicksburg. 



C. LiNTEA. PI. 11, fio-. 7 and PI. 13, fig. 4. — Ovate, elevated, ventricose, with four approximate equal 

 impressed lines ; base ventricose, profoundly striated ; labrum margin much thickened, profoundly 

 striated ; summit of the labrum prominent ; base slightly produced. Length 6-10. Rare. 



NARICA. 



N. MISSISSIPPIENSIS. PI. 11. fig. 8. — Subglobose, revolving lines fine, regular, equal; longitudinal wrinkles 

 very minute ; spire very short; suture somewhat channelled; umbilicus rather large. Length 4-10. 



SIGARETUS. 



S. MISSISSIPPIENSIS. PI. 1 1 fig. 9. — Obliquely oval, with fine very closely arranged wrinkled revolving lines ; 

 whorls convex ; no umbilicus. Length 8-10. 



This species is usually much smaller than the specimen described, and scarcely 

 differs from a species of Claiborne, Alabama. Not very common. 



