DESCRIPTION. 157 



pearlaceous ; columella white ; grooves obsolete 

 on the under part ; umbilicus circular, perforate. 

 Inhabits 



Fig. 7. T. scalaris. 



Shell conical, cancellate, or ribbed longitudi- 

 nally ; whorls distant. 



D' Argenville Conch. Tab. 11. Fig. 5. 



Specimen white, umbilicate, imperforate ; no 

 solid columella ; whorls round, connected by the 

 longitudinal, carinate, sub-oblique ribs, which are 

 not continuous, but encompass each whorl sepa- 

 rately, and adhere to each other at the upper and 

 lower part ; extremely thin and brittle. 



Inhabits the coast of Barbary. 



Fio;. 8. T. Terebra. 



Shell tapering ; whorls with acute carinate striae. 



Lister Conch. Tab. 590. Fig. 4. 



Specimen brownish white ; whorls rather convex. 



Inhabits European, African, and Chinese shores. 



