Kb TRACHELIPODA. 



Three-fourths of an inch long. Inhabits the rivers of the Ar- 

 chipelago. 



Genus 65.— MELANIA Lamarck. 



Generic Character — Shell turrited j aperture entire, ovate or 

 oblong : effuse at the base ; columella smooth, and incurvated ; 

 with a horny operculum. 



Melania amarula — The Crowned Melania. Plate XIII. 

 fig. 8. Ovate-oblong, thick ; longitudinally wrinkled ; trans- 

 versely striated at the base of the body ; upper margin of the 

 volutions crowned with triangular tubercles, from which eman- 

 ate ciliated spines ; colour deep chestnut, covered with a black 

 epidermis. One and a half inch long. Inhabits the rivers of 

 India. 



FAMILY VIII. LYMNiECEA. 



The animals of this tribe are amphibious, usually without an 

 operculum \ and having flattened tentacula ; shell spiral, generally 

 smooth on the external surface ; the margin of the outer lip is 

 always acute, and not reflected. 



Genus m.—hYM^ Mk.—Bruguiere. 



Generic Character — Shell oblong, sometimes turrited; spire 

 produced ; aperture entire, oblong ; the outer lip acute ; the 

 lower part of the inner lip rising on the columella, and forming 

 an oblique plait ; destitute of an operculum. 



Lymncea stagnalis. — The Pond LvMNiEA. Plate XIII. fig. 

 9. Oblong, body ventricose ; spire very acute and subulate ; 

 aperture large and ovate ; horn-coloured. Two inches long. 

 Inhabits the ditches and ponds of Europe. 



Genus 67. ^FHYS A.— Drapernaud. 



Generic Character. — Shell generally sinistral, convolute, oval, 

 or oblong ; spire prominent ; aperture longitudinal, contracted 

 above; columella twisted ; outer lip very thin, acute, partly 



