October, 1843.] 309 



body whorl, prominent, flattened laterally, and crossed by prominent alternate 

 stria?, the larger ones rather distant and elevated ; columella with 3 plaits, recti- 

 linear; base subumbilicated ; aperture nearly half the length of the shell. 

 Length, half an inch. 

 From Maryland. 



Oliva. 



O. duplicata. Elliptical; spire conical, volutions 5, rectilinear; labrum 

 about half as long as 'the shell ; aperture less, caused by a thick deposit on the 

 upper part of the columella, which extends more than half the distance from 

 the summit of the labrum to the suture ; labrum with a rectilinear margin ; 

 aperture narrow and somewhat oblique. Length, half an inch. 



Locality. Wilmington, N. C. Mr. Hodge. 



Ptramidella. 



P. arenosa. Subulate, whorls 9 or 10, with rectilinear sides; a deep angu- 

 lar channel at the suture, minutely crenulated ; channel passing over the mid- 

 dle of the back of body whorl, and the superior margin carinated ; columella 

 with 2 plaits, the superior one profound and acute. Length half an inch. 



Locality. Suffolk, Virginia. 



Fusus. 



F. migrans. Fusiform, elongated ; surface with crowded unequal impress- 

 ed spiral lines, and strong arched lines of growth ; whorls contracted above, 

 rounded towards the suture ; whorls near the apex longitudinally ribbed ; aper- 

 ture half the length of the shell ; beak much recurved. Length, three inches 

 and a half. 



Locality. Calvert cliffs, Md. 



F. devexus. Fusiform, with obtuse longitudinal ribs, obsolete near the up- 

 per margin where the whorls are somewhat contracted; ribs on the body whorl dis- 

 appear just below the angle; above which the whorl is flattened, wide and pro- 

 foundly declining ; surface with robust, prominent and fine intermediate spiral 

 lines ; aperture more than half the length of the shell ; beak sinuous. 



Locality. Occurs with the preceding species. 



Length, two inches. 



Voluta. 



V. mutabilis. (Fasciolaria mutabilis,) Journ. Acad. Nat. Sciences, vol. vii, 

 p. 135. Silliman's Journ. vol. xli. p. 136, pi. ii., fig. 7. 



Ovuia. 



O.iota. Narrow-elliptical, with minute spiral lines towards the base ; inner 

 margin regularly arched above the middle of the shell, where the aperture is very 

 narrow, widening a little towards the apex ; aperture gradually expanding from 

 the middle to the base ; labrum very slightly rounded ; labium reflected. 



Length, quarter of an inch. 



Locality. Calvert cliffs, Md. 



Monobonta. 



M. exoluta. Depressed; volutions slightly convex, with revolving lines, most 

 prominent on the periphery and base; 7 or 8 lines on the base increasing in 



