57 



concealed by the last whorl, with a callus reaching from the lip over 

 the summit : labrum rather sharp, finely denticulate within : columel- 

 la with five, plaits, the anterior of which are larger. This species 

 resembles M. frumentum Soiob. 



Length .17 inch ; breath .11 inch, 



MiTRA MONiLiFERA. Shell between a fpsiform and rhomboidal 

 shape : brownish black, with a white spiral band which is a little 

 above the suture, and which is small and indistinct on the upper whorls 

 and increases with the progress of growth, and which is dilated into 

 spots on the ribs ; with rather acute longitudinal ribs, about fourteen 

 on each whorl, and numerous excessively minute unequal raised spiral 

 lines, which are larger at the anterior extemity, and more nodulous 

 on the ribs ; anteriorly with a broad well impressed groove, which 

 commences in the aperture above the plaits, and contracts the general 

 form: apex acute: spire with nearly rectilinear outlines: whorls eight 

 or nine, rather convex, with a rather deep suture : columella with 

 four plaits. 



Mean divergence 45^ ; length of spire .38 inch ; total length .74 

 inch ; breadth .36 inch. 



This species resembles 3f. microzonias Lam. in which the ribs are 

 obtuse, the outlines of the spire are more convex, and the general 

 form is narrower. It also, resembles M. leucodesma Reeve. 



MiTRA. ALBicosTATA. Shell fusiform : dark brown or reddish 

 brown, with whitish ribs, with a spiral band of a darker shade of the 

 same, which is scarcely interrupted on the ribs, and a spiral white 

 band which commences on the last whorl near the summit of the ap- 

 erture : with obtuse longitudinal ribs, about IG on each whorl, which 

 are nearly obsolete in a broad shallow groove near the anterior ex- 

 tremity ; with spiral striiB in the intercostal spaces, and a few spiral 

 raised nodulous lines anteriorly, of which the larger is continuous 

 with the upper columellar plait : apex obtuse : spire with the outlines 

 quite convex : whorls six, moderately convex, with a well impressed 

 suture : aperture narrow : columella with four plaits, of which the 

 two lower are small and approximate, and the two upper are large 

 and distant. This species resembles M. cavea Reeve. 



Mean divergence 40°. Length of spire .35 inch ; total length .59 

 inch ; breadth .31 inch. 



CoLUMBELLA'FENESTRATA. Shell mucli elongated, ovate conic, 

 sub-angular on the middle of the last whorl : opaque white around 

 the aperture, with, at the summit of the whorls, a spiral opaque white 

 band, which is interrupted by the angles of an approximate series of 



