16 



10. Gaimardi, Adams. 



11. granulosa, Rectus. 



12. Gueriniana, id. 



13. helicoidea, Le Guill. 

 1-i. lamellosa, If Orb. 



15 . ligata, Recluz. 



16. Mauritiana, Recluz. 



17. Orbignyana, id. 



18. Petitiana, zV?. 



19. plicata, id. 



20. Quoyi, id. 



21. rosea, e'c?. 



22. rugata, Adams. 



23. Sigaretiformis, Po£. 



24. Souleyetiana, Recluz. 



25. striata, B'Orb. 



26. sulcata, i<#. 



Figure, 



Narica cancellata. PL 16. Fig. 81. Shell, showing its white, can- 

 cellated substance and light umbilicated growth. 



Genus 5. VELUTINA, Fleming. 



Animal ; bulky ; head short, broad, bearing two rather obtuse, 

 subulate tentacles, separated at their bases by the breadth of 

 the head ; on bulgings at their origins externally are the eyes ; 

 proboscis retractile ; mantle ample, thick, more or less reflected 

 on the shell all round ; foot large, obtusely quadrate in front, 

 rounded behind ; branchial plumes two. (Forbes.) 



Shell; subglobose, thin, more or less coriaceous, slightly umbili- 

 cated, covered with a thin epidermis ; whorls few ; spire short; 

 last whorl ventricose ; aperture large, rounded, entire ; lip 

 simple. 



A genus of light, inflated, rosy-mouth shells, of northern habitation, 

 dwelling at low-water mark, and often far out at sea at considerable depth, 

 chiefly in the Arctic and boreal provinces of Europe and North America. 

 Linnajus, uninformed of the strictly marine nature of this mollusk, in- 

 cluded the species known to him in his genus Helix ; but his contem- 

 porary, Miiller, referred it, more naturally, to Bulla. The shell is of rather 

 fragile substance, with mostly only a very slight secretion of calcareous 

 matter beneath the epidermis. We include two nearly allied forms de- 

 scribed by British authors in the genera Lamellaria and Otina. 



1. antarctica, Couth. 



2. capuloidea, Blainv. 



Species. 



3. Caspiensis, Adams. 



4. conacea, Pallas. 



5. cryptospira, Midd. 



6. glacialis, Couth. 



