GASTEROPODA. 



Fossil, V. Lamberti, Crag, Suffolk. 



231 



Melo, Brod. Large, oval ; spii'e short. 

 Type, M. diadema, PL YII., Fig. 11. New Guinea, 8 species. 



Cymba, Broderip. Boat-shell. 



Synonym, Yetus (Adan-s.), Gray. 



Type, G. proboscidalis, PL VII., Pig. 12, 

 and Fig. 91 (= Y. cjTnbium, L.). 



Shell like yoluta ; nucleus large and 

 globular; whorls few, angular, forming a 

 flat ledge round the nucleus. 



The foot of the animal is very large, and 

 deposits a thin enamel over the under side 

 of the shell. It is ovo-viviparous, and 

 the young animal is very large when born ; 

 the nucleus becomes partlj'' concealed by the 

 growth of the shell. 



Distribution, 10 species. West Africa, 

 Lisbon. 



rig. 91. Cymha. 



MiTRA, Lam. Mitre-shell. 



Synonyms, Turris, Montfort. Zierliana, Gray. Tiara, Sw. 



Types, M. episcopalis, PL YII., Fig. 13. M. vulpecula 

 Fig. 14. 



Shell fusiform, thick ; spire elevated, acute ; aperture small, 

 notched in front ; columella obliquely plaited ; operculum very 

 small. 



The animal has a very long proboscis ; it emits a purple 

 liquid, having a nauseous odour, when irritated. The eyes are 

 placed on the tentacles, or at their base. Eange, from low 

 water to 15 fathoms, more rarely in 15 — 80 fathoms. 



Distribution, 420 species. Philippines, India, Bed Sea, 

 Mediterranean, West Africa, Greenland (1 species). Pacific, 

 West America. The extra-tropical species are minute. M. 

 Oreenlandica and M. Cornea (Mediterranean species) are found 

 together in the latest British Tertiaries. (Forbes.) 



Fossil, 90 species. Chalk — . India, Britain, France, &c. 



Sub-genera. Imhricaria, Schum, (conoelix, Sw.) 

 Shell cone-shaped. I. conica, PL YII., Fig. 15. 

 Cylindra, Schum. (Mitrella, Sw.) 

 Shell olive-shaped. C. crenulata, PL YIL, Fig. 16. 



