MUSEUM OF COMPARATIVE ZOOLOGY. 363 
No internal shell-plate. 
Jaw smooth, with a median projection. —. 
Lingual membrane with tricuspid centrals, bicuspid laterals, quadrate mar- 
ginals, 
Java, Ceylon, Cape of Good Hope, Guinea. 
For figure of lingual dentition, see Heynemann, Malak, Blatt., XIV., Pl. IT. 
Anadenus, HEYNEM. 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 : external respiratory and anal orifices on the right 
posterior margin of the mantle ; orifice of the combined genital system behind 
and below the right eye-peduncle. 
Internal shell-plate small, oval, flat, with posterior nucleus and concentric 
striæ. 
Jaw with numerous ribs. 
Lingual membrane with tricuspid centrals, bicuspid laterals, and quadrate 
marginals. 
Himalaya Mountains. 
For figure of shell-plate and lingual dentition, see Heynemann, Malak, Blatt., 
5.090 Ble ¡La 
Arion, Fer. (Prolepis, Lochea, 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 respiratory 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, Mórch. Animal limaciform, subcylindrical, tapering behind : 
tentacles simple: 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, 
