MANUAL OF CONCHOLOGY. 



Family ACHATINIDJE. 



Holopod, sigmurethrous snails with ithe central tooith of the 

 radula very narrow (with few exceptions), its cusp small or 

 absent, the side teeth tri cuspid or bicuspid. Jaw generally 

 striated. Genitalia with no accessory organs. Kidney two or 

 three times the length of the pericardium. Pulmonary vein 

 without large branches. Shell ovate, turrited or cylindric, 

 well developed and capable of containing the entire soft parts ; 

 the columella frequently truncated below. 



Distribution, tropical and subtropical regions throughout 

 the world. 



These snails differ from Bulimulid& by the long kidney, 

 from Acwvida by the very diverse venation of the lung and 

 the different dentition, and from 1ihe multiform group Heli- 

 cid& chiefly by the narrow central tooth of ithe radula and 

 the structure of the shell. Up to this time no Heliciform or 

 slug-like AchatinicUe have been made known, but such types 

 probably exist in so large and varied a family. 



While widely distributed in the tropics, mostt of the genera 

 are confined to Africa and middle America. In tropical 

 Africa the number and variety of species is very great, and 

 they occupy that region almost to the exclusion of other groups 

 of Holopod snails, excepting ithe carnivorous Streptaxida. 

 The African Ackatinida fall into three groups which may be 

 rated as subfamilies, although the absence of full anatomical 

 data at the present time renders any classification provisional. 



I. Subfamily ACHATININ^E. Mostly capacious shells, ovate 

 or rarely subcylindric, usually decorated with zigzag 



(Til) 



