346 On the Secondary and Tertiary Formations. 



Cyprjea. 

 Cyprcpu CaroUnensis. Plate II, fig. 6. Ovate, ventricose, superior 

 margin of the labrum prominent at the apex ; base plano-convex. 



Fasciolaria. 

 Fasciolaria mutahilis. Plate II, fig. 7. For description, see Journ. 

 Acad. Nat. Sci., Vol. vii, p. 135. 



DiSPOTCEA. 



Dispotoea vmltilineata. Plate II, fig. 8, Subovate, depressed ; apex 

 prom.inent ; one side with squamose lines, the opposite with finer ramose 

 lines destitute of scales ; diaphragm contracted. 



B. dicmosa. Plate II, fig. 9. Elevated, with ramose radiating lines 

 and obsolete ribs, and with erect tubular spines ; apex minutely spiral. 



Cassis. 

 Cassis Hodgii. Plate II, fig. 10. Elliptical, with numerous spiral 

 lines most prominent towards the base ; spire conical, volutions convex. 



Pectunculus. 



Pectunculus quinquerugatus. Lentiform, with very fine crowded 

 longitudinal strise, and convex slightly raised ribs ; behind the umbo are 

 five or six recurved plicas or undulations. Length, 3f inches. 



P. CaroUnensis, Lentiform, thick, posteriorly subcuneiform ; ribs 

 obsolete, radiating striae strongly marked, minutely granulated ; cardi- 

 nal plate broad and thick ; teeth obsolete ; inner margin with numerous 

 crenulations. Length, If inches. 



P. aratus. Obovate, with about twenty eight ribs, about as wide as 

 the intervening spaces crossed by wrinkled lines ; posterior margin ob- 

 liquely truncated above the extremity, which is angulated ; margin with 

 about fifteen wide crenulations. Closely allied to P. pectinatus. 



Mactra. 



Mactra crassidens. Plate II, fig. 11. Triangular, thick, convex- 

 depressed ; umboidal slope submarginal, angulated ; beaks central ; 

 cardinal plate thick, lateral teeth robust. This species is from Mr. 

 Smith's collection. It belongs to the genus Mulinia of Gray. 



M. subparilis. Plate II, fig. 12. Triangular, elongated, moderately 

 thick, convex-depressed ; posterior side cuneiform ; apex hardly ob- 

 lique, subcentral ; fosset wide ; lateral teeth transversely striated. Be- 

 longs to the genus Spisula, Gray. 



LUCINA. 



Lucina trisulcata. Obovate, convex ; with concentric lines, and two 

 or three distant concentric furrows ; lunule profound. Differs from L. 

 alveata of the lower tertiary in being less ventricose, and in the much 

 more profoundly impressed lunule ; the cardinal teeth are also very 

 different. 



