28 



not strongly defined; surface marked by strong, elevated 

 striae, which cross the volutions from the upper side ob- 

 liquely or with a gentle curve backwards, and, crossing the 

 spiral band, which is coincident with the angle of the volu- 

 tion, appear below it in a nearly vertical, or slightly oblique, 

 position to the axis of the shell; form of aperture unknown. 



Length *33 of an inch. 



Locality. — Bloomington, la. 



This very elegant little species differs from any of the 

 others, in the strong transverse striae, the angulation of the 

 volutions near the lower edge, and the absence of revolving 

 striae. 



Murchisonia terebriformis. — Shell extremely elongate, 

 subulate-acute ; volutions eight or nine, very convex, 

 marked by a broad spiral band in the centre, last volu- 

 tion ventricose ; suture deeply marked ; surface ornamented 

 on the upper side of the volutions by fine striae, which ex- 

 tend obliquely backwards to the spiral band, below the 

 band by one or two spiral elevated striae, and on the last 

 volution by four or five similar striae ; aperture unknown ; 

 umbilicus none. 



Length '33 of an inch. 



Locality. — Bloomington, la. 



LOXONEMA, Phillips. 

 Loxonema Yandellana. — Shell terete-subulate ; spire 

 elongate, very gradually tapering to the apex, which is ap- 

 parently obtuse ; volutions about eight or nine, very little 

 convex, the last one scarcely expanded ; suture distinct ; 

 surface marked by fine thread-like striae crossing the volu- 

 tions with a slight undulation above the middle ; aperture 

 ovate. 



Length *20 to *50 of an inch. 

 Locality. — Spergen Hill, la. 



Loxonema vincta. — Shell extremely elongate, very grad- 



