CONTHNTS. 



i>A<.r;. 



Introduction ■ 



Description of Genera and Species, with a Discussion of their Genetic 



Relationsliips 7 



A. The genus I'ltsits 7 



1 . Eocene species of Fushs 1 1 



2. The Fiisiis cuius series iX 



3. Piisus tiihcrculatiis and its allies 30 



4. The Fusus distaits series 36 



5. The Fusus iungissimus series 40 



6. The Fusus hcckii series 43 



7. Fusus dupctit-tliouarsii and its allies 46 



8. The Fusus longirosfris series 52 



9. The Fusus rostratus series 58 



10. Ihe Fusus australis series 65 



11. Species of Fusus. whose precise relations are undetermined 72 



B. Species of Fusoid shells generally referred to Fusus 7^ 



12. The Genus .If^fyxis 7^ 



13. Eocene species generally referred to I'usus 80 



14. The genus Hcilpriiiia ( gen. nov.) 87 



15. The genus Eiithrio fusus 93 



C. Phylogerontic Fiisida 96 



16. The genus Cyrfulus 96 



17. The Eocene Clavilithoids 98 



Geographical distribution 145 



Literature 153 



Descri])ti(>n of plates I-XVHI if'O 



