238 



THE LIAS AMMONITES. 



I. ArCESTIDjE. 



1. Arcestes, Suess. 



3. DiDYMiTEs, Mojsisovics. 



3. LoBiTES, Mojs. 



4. Ptychites, Mojs. 



9. Tropites, Mojs. 



10. Trachyceras, Laube. 



11. Choristoceras, Mojs. 



5. Pinacoceras, Mojs. 



6. Sageceras, Mojs. 



7. Amaltheus, Montfort. 



8. Schloenbachia, Neumayr. 



II. TROPITIDiE. 



12. Rhabdoceras, Suess. 



13. CocHLOCERAS, Hauev. 



III. LYTOCERATIDiE. 



14. Lytoceras, Suess. 



15. Hamites, Parkinson. 



16. Turrilites, Lamarck. 



17. Baculites, Lamarck. 



18. Phylloceras, Suess. 



IV. AEGOCERATIDiK. 



19. Aegoceras, Wuagen. 



20. Arietites, Waag. 



21. Harpoceras, ^«fly. 



22. Oppelia, Waag. 



23. Haploceras, ^2We/. 



24. Stephanoceras, 7/^««(J'. 



25. Cosmoceras, Waag. 



26. Ancyloceras, d' Orhigny. 



27. Baculina, d'Orbig. 



28. SlMOCERAS, ZzVif. 



29. Perisphinctes, F««y. 



30. Olcostephanus, Neumayr. 



31. ScAPHiTES, Parkinson. 



32. HopLiTEs, Neuni. 



33. AcANTHOCERAs, Ncum. 



34. Stoliczkaia, Nemn. 



35. Crioceras, Leveille. 



36. Heteroceras, d'Orbig. 



37. Peltoceras, Waag. 



38. ASPIDOCERAS, ^2#." 



Note. — The diagnoses of the families are here given in abstract from Prof. Neumayr's work. 



I. Family. — Aecestid^e, Mojsisovics. 



Shell smooth or provided with transverse folds, ribs, or longitudinal lines. The wrinkle- 

 layer (Runzel-schicht)^ present in the naore ancient forms ; the lobes consist mostly of 

 short, abruptly interrupted lines, seldom (only in Sageceras) granular. Mantle-impression, 

 in the forms from the Trias, with more or less contraction around the mouth-opening 



1 This word has no equivalent in the English language, but it clearly means the wrinkled marginal 

 layer of the mantle of the Mollusc, which formed the lobe-lines of the septa, and imparted such an 

 important character to the shells of the Araraonitidse. 



