OF MOLLUSCA. 61 



lobed flap on the upper surface in front. Head seldom protruded 

 beyond the transparent shell. — Alder. 



1. L. bilineata, Adams, Gen. Moll. t. 25. f. 3. Eulima b., Forbes 

 $• Hartley, B. M. t. K.K. f. 5. 



8. Menestho. 

 " Animal : Foot elongate, narrow. Mouth simple ; lingual mem- 

 brane none. Tentacles short, thick. Eyes small, at the inner base 

 of the tentacles. Operculum few-whorled. Shell conical, turrited." 

 — Moller. 



1. M. albula, Moller, MSS., cop. Gray, Fig. Moll. t. 125. f. 2, & 

 Adams, Gen. Moll. t. 24. f. 10. 



9. Aclis, 



Shell turrited ; whorls many, convex, striated. Mouth oval or 

 rounded ; pillar lip without folds ; axis perforated or subperforated. 



1 . A. supernitida, Forbes fy Hanley, B. M. t. M.M. f. 5, & Adams, 

 Gen. Moll. t. 24. f. 9. 



Animal of Aclis supernitida slender, head truncate. Tentacles 

 slender, cylindrical, rather inflated at the tip, close at the base. Eyes 

 immersed, basal, rather lateral. Proboscis long, strong, retractile. 

 Tongue armless. Chin free. Foot very narrow, produced. Oper- 

 culigerous lobe unequal, right side larger, three- or four-plicate, left 

 side with a rounded lobe. Operculum ? — Lovin. 



The animal of Aclis supernitida with an elongate produced men- 

 tum, rather enlarged, truncated at the end. Tentacles two, lateral, 

 far back. Eyes on the inner side of the base of the tentacles, seen 

 through the shell. 



10. Hyala. 



Shell subcylindrical ; whorls rounded, last very large ; axis imper- 

 forate ; outer lip acute. Animal : muzzle bilobate. Tentacles sub- 

 ulate, flattened, blunt. Eyes small, basal, superior, and central. 

 Foot broad, two-lobed in front. Operculum roundish, thin. 



1 . H. vitrea (Risso v.), Forbes fy Hanley, B. M. t. M.M. f. 6 ; cop. 

 Adams, Gen. Moll, t. 34. f. 7. 



c. Shell living in holes in starfish or on spines of Echini. Opercu- 

 lum none 1 



11. Stylina. 



Shell subglobose, thin, smooth, polished ; whorls many ; apex 

 acuminated, produced, styliform ; mouth rather large, subovate, 

 rounded before ; pillar Up thin, curved, smooth. 



Tentacles slender, cylindrical, with the small immersed eyes at 

 their external bases. Mantle thick, fleshy, reflexed on the last 

 whorl of the shell. Foot large, long, tongue-shaped, produced into 



