86 GENERA OF SHELLS. 



PURPURIFERA. 



Shell with a short canal ascending posteriorly, or an oblique 

 notch or demi-canal at the base of the aperture, directed to- 

 wards the back. 



Div. I. CANAL ASCENDING OR CURVED TOWARDS 



THE BACK. 



CAS SID ARIA. Shell obovate, or ovate ob- 

 long. Aperture longitudinal, narrow, termin- 

 ating at base, in a curved, subascending canal. 

 Lap varicose or reflected ; pillar lip covering 

 the columella, often rough, granular, tubercu- 

 lous or wrinkled. 



Distinguished from cassis by being, in general, less 

 inflated, but chiefly by its short canal, not being ab- 

 ruptly turned towards the back of the shell and being 

 but slightly curved or ascending. The spire is short, 

 without continuous varices : the columella is generally 

 loaded with small, oblong, wrinkled tubercles lying in 

 a transverse direction. 



(a.) Spire having 1 varices. 



C. echinophora, thyrrena, cingulata, striata, oniscus, 

 cancellata, carinata, flammea, fasciata, glauca, crumena, 

 plicaria, areola, zebra, decussata, abbreviata. 

 (>.) Spire without varices. 



C. rufa, pennata, testiculus, achatina, pyrum, zeylanica, 

 sulcosa, granulosa, saburon, canaliculata, semigranosa, vibex, 

 erinaceus, harpseformis. 



CASSIS. Shell inflated. Aperture longi- 

 tudinal, narrow, terminated at base by a short 

 canal, turning abrupt backwards. Columella 



