46 BOOK OF SPECIES. 



flammules ; whorls convex, about ten ; sutures 

 somewhat hollowed; spire acute. |. W. Sup. 



8.72. 



MELA MOPS IS. FLUVIATILE. 



Turreted; aperture ovate-oblong, entire; columella 

 with a callosity above, truncated at the base, 

 and incurvated, the outer separated from the 

 inner lip by a sinus ; operculum horny. 



M. LEViGATA. Ovate-conic^ smooth, chest- 

 nut, with seven very slightly convex whorls ; the 

 last longer than the spire. |. W. S. 4. 28. 



PIRENA. FLUVIATILE. 



Turreted; aperture longitudinal; outer lip acute, 

 with a distinct sinus at the base, and another 

 at its junction with the body'; base of the 

 columella turned towards the right ; operculum 

 horny. 



P. TEREBRALis. Turrctcd, subulate, smooth, 

 and black ; whorls flattened ; aperture white ; 

 apex generally eroded. 3. W. 25. 40. 



P. AURiTA. Turreted, muricated, reddish ; 

 whorls armed in the middle with obtuse com- 

 pressed tubercles ; aperture white ; apex eroded. 

 There is sometimes a white band near each suture. 

 IJ. W. 25. 41. 



