46 BOOK OF SPECIES. 
flammules; whorls convex, about ten; sutures 
somewhat hollowed; spire acute. ?. W. Sup. 
8. 72. 
MELANOPSIS. 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. 3. W.S. 4. 28. 
PIRENA. FLUVIATILE. 
Turreted ; aperture longitudinal; outer lip acute, 
with a distinct sinus at the base, and another 
at its gunction with the body; base of the 
columella turned towards the right ; operculum 
horny. 
P. TEREBRALIS. Turreted, subulate, smooth, 
and black; whorls flattened; aperture white; 
apex generally eroded. 3. W. 25. 40. 
P. aurira. 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. 
12. W. 25. 41. 
