14. Odostomia. Fleming. 



Spire produced ; mouth 

 contracled , sub angular , 

 distinct from the body 

 whorl. 



( 30 ) 



With teeth or plates. 



(Ellipsostomata.) 



The greater number 

 terrestrial; under stones , 

 on rocks, and in mosses. 



Animal unknown. 



Marine and Terres- 

 trial. 



V. Animal, p. 62. 



a. Spire dextral. PI. 8, fig. 28. 



b. .. sinistral. PI. 8, fig. 23. 



15. Pupa. (1) Lam. 



Summit obtuse ; mouth With or without teeth 

 narrowed b y a callous pad , or plates . 

 and diminished on the side 

 of the spire by the prece- 

 ding whorl. PI. 6, fig. 37, 

 34. 



{a Without a tooth, pi. 8, fig. 29. 

 b A tooth in the part of the mouth invaded by the pcnulti- 

 timate whorl, pi. 8, fig. 32. 

 c Teeth within the outer lip, pi. 6, fig. 37. 

 Oval f d Ghon( jrus, Cuv. Teeth at the lip, or plates within the mouth, 

 1 pi. 8, fig. 24. 



C. Horizontally volute ; mouth transpersally elliptical. 

 16. Planorbis. (2) Brug. 



Rolled almost in the 

 same plan ; the whorls in- 

 creasing gradually ; no 

 operculum. PI. 6, fig. 32. 



17. Helix. (3) 



Globulous or subcorneal, 

 spire depressed ; mouth 

 somewhat diminished by 

 the projection of the pen- 

 ultimate whorl. PI. 7. 



Stagnant waters. 

 V. Animal, p. 63. 



Terrestrial. 



V. Animal, p. 62. 



(1) The shells oi the marine and terrestrial Pupae are similar, but an experienced 

 Conchologist may always distinguish them : the animal of the former is not known. 

 Lamarck doubts the Pupa mumia to be marine. Foss. in the 2d Fresh Water 

 Formation. 



(2) Fossil species have been found in the Limestone of Fontaincbleau (2d Fresh 

 Water Formation) ; in the Silcx near Paliscau (2nd Fresh Water Formation) ; in the 

 Blame Blanche covering the Gypsum at Pantin and Chaumont (1st Fresh Water For- 

 mation) ; in the Coives Rock of Limestone ; London Clay; Green Sand ; Under Oolite; 

 Derbyshire Peak Limestone. Neither of the three Planorbes cited at Grignon can be 

 exactly referred to this Genus ; the Carinata resembles the Delphinttia. 



(3) The distinction of fresh water formations, so precisely established by Geo- 

 logists, has made it indispensably necessary to study this Genus attentively. An ar- 

 rangement with a view of easily distinguishing the species is difficult, from the 

 great accumulation, for whilst the shells present the greatest varieties of form, the 

 animals offer no differences of any importance. As M. de Ferussac appears to 

 have studied the excessively numerous species of this Genus more completely than 

 any other author, accompanying the publication of his system, which comprehends 

 all the known species, with accurate and beautiful engravings, I shall adjoin his 



