40 SYSTEMATIC ARRANGEMENT 



The tentacles of Ranella crumena are subulate, with the eyes at 

 the outer side of their bases. The proboscis is very elongate, and 

 the teeth 3 • 1 • 3. The operculum ovate, subacute at each end, 

 with the nucleus in the middle of the inner slightly curved edge. 



c. Siphon short j canal reduced to a notch; mouth narrow. Ani- 

 mal and operculum unknown. 



8. Oniscia. 



Shell subconic, tapering in front ; mouth linear ; canal short, 

 recurved ; inner lip granular ; outer lip reflexed, rounded, plaited 

 across. Animal and operculum ? 



1. O. cancellata. 



9. Morcm. 



Shell obconic, tapering in front ; mouth linear ; canal short, trun- 

 cated, scarcely recurved ; inner lip inflexed, thickened, granular ; 

 outer one thin, toothed on the edge internally, with a thickened 

 shelving outer edge. Animal and operculum ? 



1. M. oniscus. 



10. ClTHARA. 



Shell ovate, elongate ; spire conic ; whorls concentrically ridged ; 

 mouth linear, slightly channeled at each end ; inner lip thin, rather 

 expanded, cross-grooved ; outer sharp-edged, with a thick shelving 

 outer edge; throat grooved. Mantle enclosed. Tentacles subulate. 

 Foot broad ; siphon short, recurved. Operculum none. 



1. C. Citharella. 



2. C. marginelloides, Adams, Gen. Moll. t. 10. f. 9. 



11. Pachybathron. 

 Shell oblong ; spire very small ; whorls cancellated ; mouth linear, 

 channeled at each end ; inner lip rather dilated, cross-ridged ; outer 

 thickened, internally toothed. 



1. P. cassidiformis, Adams, Gen. Moll. t. 20. f. 4. 



Fam. XIII. DOLIIDjE. 



Head truncated. Proboscis very long, dilated at the end. Ten- 

 tacles moderate. Eyes on outer side of base. Mantle enclosed. 

 Siphon recurved. Lingual membrane broad. Teeth 3 ■ 1 ■ 3 ; cen- 

 tral tooth broad, three-lobed. Foot large, truncated in front. 

 Operculum none. 



1. DOLIUM. 



Shell subglobose, ventricose, spirally grooved ; spire short ; last 



