30 SYSTEMATIC ARRANGEMENT 



Trunk ofMitra episcopalis very long, cylindrical, exsertile, smooth, 

 and ringed externally. Teeth 1 • 1 ■ 1 ; central narrow, brown, 

 transverse, with five strong teeth ; lateral elongate, more than twice 

 as long as the central one, transparent, with strong denticulations on 

 the inner edge, gradually becoming smaller and more indistinct 

 towards the outer end. 



Proboscis of Mitra Ticaonica very long, large. Teeth 1 • 1 ' 1 ; 

 central broad, with an arched front edge with eight subequal, conical, 

 rather distant teeth, the outermost rather smaller; lateral teeth 

 broad, transverse, with a series of many, rather distant, conical 

 teeth on the front edge, the outermost the smallest. 



5. Strigatella. 



Shell fusiform, smooth ; pillar with five plaits ; outer lip smooth 

 within, with a large subcentral, internal thickening, leaving a pos- 

 terior groove. Animal ? Teeth ? Operculum 1 



1. S. zebra. 



2. S. acuminata. 



6. Zierliana. 



Shell ovate, fusiform, thick ; pillar with five plaits ; outer lip 

 thickened. 



1. Z. Ziervogelii. 



7. Volvaria. 



Shell cylindrical; spire very short; whorls compressed; mouth 

 linear. Animal and operculum unknown ; being only found in the 

 fossil state. 



1 . V. bulloides. 



8. Imbricaria. 

 Shell obconic, smooth ; spire conical ; mouth linear ; pillar 

 with five plaits, the largest in the middle of the inner lip ; outer 

 lip simple, crenulated, smooth within. Animal. Foot folded longi- 

 tudinally. Tentacles close ; eyes on outer side above the base. Siphon 



elongate, simple. Proboscis elongate, slender. Teeth ? Penis 



very large, elongate. Operculum none. 



1. I. marmorata, t, 45*. f. 3, 4. 



2. I. conovula, t. 106. f. 7. 



9. Cylindra. 



Shell oblong, subcylindrical, spirally grooved; mouth linear; 

 pillar with six or seven folds, the hinder larger, transverse, in the 

 middle of the inner lip ; outer lip crenated, smooth within. Ani- 

 mal. Proboscis very long, covered with conical tubercles about as 

 long as broad. Teeth 1 Operculum ? 



1. C. nucea, Adams, Gen. Moll. t. 19. f. 5. 



2. C. crenulata. 



