PREFACE. 



The greater part of this volume is occupied with a review 

 of the family Oleacinida. This was undertaken primarily 

 to find place for numerous species described originally as 

 Achatina, Stenogyra, Spiraxis etc., in other systematic works 

 referred mainly to the Achatinide or Stenogyridce, but now 

 known to belong to the Oleacinidce. The work has been ex- 

 tended to supplement the account given in Vol. I of this 

 series, bringing the subject up to date. 



In order to define clearly the position of the Oleacinida in 

 the system of land snails, the foundation of a new classi- 

 fication of the rapacious snails is briefly outlined, and 

 evidence is presented to show the polyphyletic constitution 

 of the so-called "Agnatha," or " Testacellidae ' ' of authors. 



The remainder of the volume treats of the Ferussacidce. 

 This family has an extensive literature in four of five 

 languages ; the long list of described species is evidence of the 

 tireless industry of erudite conchologists ; and yet, we know 

 so little of the creatures themselves that their classification 

 is still purely guess-work. The best-known member of the 

 group, Cochlicopa, is known, by data herein published, to 

 be practically identical with the terrestrial Achatinellida. 

 The pallial organs of other genera are unknown, but Ferus- 

 sacia seems, from the published information, to be an Aula- 

 copod snail. We look to European malacologists, to whom 

 living material is accessible, for information on these little- 

 known snails. The pedal grooves, pallial organs and geni- 

 talia of the common genera should be described. 



In the work on Antillean Oleacinida I have had the ad- 

 vantage of using the great collection of C. B. Adams which 

 the authorities of Amherst College with great liberality al- 

 lowed me to study. A large number of Adams' types are 



(iii) 



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