MUSEUM OF COMPARATIVE ZOOLOGY. 365 



No internal shell -plate. 

 Jaw smooth, with a median projection. 



Lingual membrane with tricuspid centniLs, bicuspid laterals, quadrate mar- 

 ginals. 



Java, Ceylon, Cape of Good Hope, Guinea. • 



For figure of lingual dentition, see Heynemann, Malak, Blatt., XIV., PI. IL 



Anadenus, Heyxem. Animal limaciform, subcylindrical, tapering behind : 

 tentacles simple : mantle anterior, concealing an internal .shell-plate : no lon- 

 gitudinal furrows above the margin of the foot, and no caudal mucus pore : a 

 distinct locomotive disk : e.xternal respiratory and anal orifices on the right 

 posterior margin of the mantle ; orifice of the combined genital sy.stem behind 

 and below the right eye-peduncle. 



Internal shell-plate small, oval, flat, Avith posterior nucleus and concentric 

 striae. 



Jaw with numerous ribs. 



Lingual membrane with tricuspid centrals, bicuspid laterals, and quadrate 

 marginals. 



Himalaya ^fountains. 



For figure of shell-plate and lingual dentition, see Heynemann, Malak, Blatt., 

 X., PI. I. 



Arion, Fer. (Prolepis, LocJtea, Baudonia, Kobeltia.) Animal limaciform, 

 subcylindrical, attenuated behind : tentacles simple : mantle small, anterior, 

 concealing calcareous grains, sometimes agglomerated into a shelly plate : lon- 

 gitudinal furrows above the margins of the foot, meeting over a caudal mucus 

 pore : a distinct locomotive disk : exterior respirator}-^ and anal orifices on the 

 anterior right margin of the mantle ; orifice of the combined genital system 

 below the last. 



Internal calcareous grains, in some species forming an imperfect shell-plate. 



Jaw ribbed. 



Lingual membrane with tricuspid central teeth, tricuspid or bicuspid laterals, 

 and quadrate marginals. 



Europe. 



For figure of animal, jaw, and lingual dentition, see Terr. Moll. U. S., V. 



Ariolimax, MdrcL Animal limaciform, .subcylindrical, tapering behind : 

 tentacles sinq)le : mantle anterior, small, concealing an internal shell-plate : 

 longitudinal furrows above the margin of the foot, meeting over a caudal 

 mucus pore : a distinct locomotive disk : external respiratory and anal orifices 

 on the posterior right margin of the mantle : orifice of combined genital system 

 on the right side of the body, below the anterior free edge of the mantle. 



Shell-plate internal, solid, flat, longer than wide. 



Jaw ribbed. 



Lingual membrane with tricuspid centrals, bicuspid laterals, and quadrate 

 marginals. 



Pacific Coast of United States. 



