the third and fourth whorls, and there sh'ghtly concave ; apex broadly 

 truncate with the loss of ten or eleven whorls ; nine or ten remaining, 

 scarcely convex, with a lightly impressed slightly marginate suture ; 

 last whorl produced perpendicularly to the axis of the spire ; aperture 

 a little dilated on the right, otherwise orbicular, a little spreading ; lips 

 well reflected only at the extreme margin. 

 Length .58 inch; breadth .163 inch. 



Cylindrella Gravesii. Shell ovate-cylindrical moderately 

 elongated, with the last whorl a little quadrangular ; white ; with very 

 dense very fine slightly arcuate very oblique striae, with the carinae 

 of the last whorl obsolete ; spire with rather convex outlines ; apex 

 truncate with the loss of whorls ; nine to eleven whorls remain- 

 ing, scarcely convex, with a lightly impressed margined suture ; last 

 whorl moderately produced at right angles to the axis of the spire ; 

 aperture somewhat quadrangular, lip rather wide, reflected into the 

 plane of the aperture. 



Var. a, with a small prominent anterior carina. 



Dimensions rather variable, as follows in three individuals before 

 me. No. 1 ; length .72 inch ; breadth .178 inch. No 2 ; length .66 

 inch; breadth .2 inch. No. 3 ; length .55 inch ; breadth .19 inch. 



Cylindrella ambigua differs from C. rosea, Pfr., in having the 

 outlines more convex, the whorls very deep. If not a monstrosity, it 

 is probably a good species ; but from a single specimen I am unable 

 to decide. 



Cylindrella rosea, Pfr. var. magna, Ad. Length 1 inch ; breadth 

 .34 inch. 



Cylindrella rosea. Pfr. var. major, Ad. Length 1.3 inch; breadth 

 .45 inch. 



The dimensions of the type are the following : length .73 inch ; 

 breadth .26 inch. 



Cylindrella aspera. Shell ovate-cylindrical, moderately elon- 

 gated ; red mostly, with white anteriorly, or sometimes white in half 

 of the shell ; with very coarse oblique stria;, which are most arcuate at 

 or below the middle, with the intervening raised lines acute-edged, 

 with a nearly obsolete carina anteriorly, and another more prominent 

 midway between this and the middle of the last whorl ; spire with 



quite convex outlines ; apex truncate with the loss of whorls ; 



nine or ten whorls remaining, quite convex, with a well impressed su- 

 ture ; last whorl moderately produced, subangular on the right side; 

 aperture large, spreading, subrectilinear above, in the rest orbicular, 



