MUSEUM OF COMPARATIVE ZOOLOGY. 365 



Hemphillia, Bl, & Binn. Animal limacifonn, blunt before, swollen at 

 centre, and greatly attenuated behind : tentacles simple : mantle subcentral, 

 large, oval, concealing all but a rounded large orifice, an internal sboU-plate : 

 longitudinal furrows above the margin of the foot and caudal mucus pore, over 

 which is a hump-like process : no distinct locomotive disk : external respiratory 

 and anal orifices at the central right margin of the mantle : orifice of combined 

 genital system near the right eye-peduncle. 



Shell-plate homy, small, unguiform, longer than wide, with posterior nucleus 

 and concentric lines of growth. 



Jaw ribbed. 



Lingual membrane with tricuspid central teeth, bicuspid laterals, and quad- 

 rate marginals. 



Coast of Oregon. 



The swollen central portion of the animal seems the first approach to a turbi- 

 nate mass of viscera, separated from the foot. 



Geomalacus, Alm. Animal limaciform, subcylindrical, blunt behind : 

 tentacles simple : mantle anterior, close to head, concealing a shell-plate : lon- 

 gitudinal furrows above the margin of the foot ? a caudal mucus pore : a dis- 

 tinct locomotive disk : external respiratory and anal orifices on the right far 

 anterior margin of mantle : orifice of combined genital system behind and 

 below right eye-peduncle. 



Shell-plate calcareous, flat, small, internal, ovate. 



Jaw ribbed. 



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

 ginals. 



Eastern Europe. 



For figure of the animal and internal shell plate, see Adams's Genera ; of 

 jaw and lingual dentition, see Heynemann, Malak, Blatt., XXL, Nachr. der 

 Malak, Gesell., T. 165, PI. I. 



Letourneuxia, BoURG. Animal limaciform, subcylindrical, scarcely atten- 

 uated behind : tentacles simple : mantle small, anterior, concealing a shell- 

 plate : no longitudinal furrows above the margin of the foot, and no caudal 

 mucus pore; no distinct locomotive disk: external respiratory and anal orifices 

 on the right anterior margin of the mantle : orifice of combined genital system ? 



Shell-plate internal, calcareous, suboval, flat. 



Jaw ribbed. 



Lingual membrane ? 



Algiers. 



There is a peculiar overhanging process to the side of the body, near the tail. 



For figure of animal, internal shell-plate, and jaw, see Bourgignat, Moll. 

 Nouv., VII., 1866, p. 201, PI. XXXIV. Fig. 7. 



Peltella, Webb & Van Ben. {Pectella, Gray.) Animal limaciform, 

 rounded above, flat below, sides widely expanded : tentacles simple : mantle 



