LIST 



OF 



MOLLUSCA. 



Family OLIVID.E. 



Siphon of mantle recurved. Head small. Foot -with a cross 

 groove on each side, in front very large, often enclosing a part 

 of the shell and producing a polished coat on it. Mantle en- 

 closed. Shell ovate cylindrical. Mouth linear, ovate ; canal re- 

 duced to a notch. Operculum horny, small, often wanting. 



Tribe I. OLIVINA. 



Shell subcylindrical, smooth, polished ; suture with a deep 

 channel; pillar plaited in front. Mantle with an elongated 

 posterior process enclosed in the groove of the spire. Lateral 

 teeth of the tongue broad ovate. Operculum with subapical 

 nucleus or wanting. 



Linnaeus divided the shells usually called Olives by the 

 dealers into three species, viz. Valuta porphyria, V. oliva, and 

 V. ispidula. 



Gmelin added a few ; and Lamarck, who published a mono- 

 graph of the genus in the 'Annales du Museum/ extended the 

 number to sixty-two, which Dillwyn reduced to eighteen. 



Duclos, who published the plates of a monograph of this 

 genus in 1835, figures eighty-four recent species ; and he con- 

 siders twenty-two of the species which Lamarck described as 

 only varieties of other species. 



