26 



two, forming the summit of the angle ; midway between 

 the angle and the suture is one strong angular stria, and on 

 the outer side, and sometimes on the inner side of this a 

 finer one. 



Length *35 of an inch. 



Locality. — Spergen Hill, la. 



Pleurotomaria, (Murchisoxia?) coxula. — Shell conical, 

 spire gradually and uniformly diminishing from the base ; 

 volutions six to eight, angular in the middle, and flattened 

 above and below ; sutures defined ; surface marked by dis- 

 tinct, elevated, nearly vertical striae both above and below 

 the spiral band ; spiral band occupying the periphery of 

 the volution, and composed of three revolving minute cari- 

 nations with narrow depressions between (sometimes only 

 two elevated bands are visible) ; aperture sub-quadrate ; 

 columella extended below, perforate. 



Length from *08 to *l8 of an inch. 



Locality. — Spergen Hill, la. 



S Murchisoxia ixsculpta. — Shell subulate-conical ; spire 

 somewhat rapidly ascending, acute ; volutions six or seven, 

 convex and rounded in the middle, appressed and sloping 

 gradually above, and abruptly below, to 'the suture ; upper 

 side of volutions marked by vertical elongate nodes, which 

 are pointed above and gradually disappear in the surface 

 below, or subdivide into distinct elevated striae ; spiral 

 band rather broad, margined by two distinct elevated lines 

 with the intermediate space convex or concave ; last volu- 

 tion ventricose, extended below, and marked by an elevated 

 line which is a continuation of the suture line ; aperture 

 somewhat rounded, and extended in front ; columella ex- 

 tended below and imperforate. 



Length from *05 to *25 of an inch. 

 Locality. — Spergen Hill ; Bloomington, la. 



MURCHISONIA, Phillips. 



