FIG. 1. Diagrammatic Section to show the chief variations in the 
Liassic Strata from Dorsetshire to Yorkshire - - 23 
,, 2. Ichthyosaurus communis, Conyb., and Coprolite, Lower 
Lias, Lyme Regis. (Guide to Department of Geology, 
British Museum, Part II., p. 34, 1890) - - 37 
,, 3. Plesiosaurus dolichodinks, Coriyb., Lower Lias, Lymo 
Regis. (Guide Dep. Geol., Brit. Mus., Part II., p. 49) 37 
4. Skull of Ichthyosaurus communis, Coiryb., Lower Lias, 
Lyme Eegis. (Guide Dep., Geol., Brit. Mus., Part II., 
p. 32) - - 38 
,, 5., Skull of Ichthyosaurus latifrons, Konig, Lower Lias, 
Barrow-on-Soar. (Guide Dep. Geol., Brit. Mus,, 
Part II. p. 33) - - 38 
t , 6. Teeth of Ichthyosaurus platyodon, Conyb., and J. com- 
munis , Conyb. , Lower Lias, Lyme Regis. (Guide Dep. 
Geol., Brit. Mus., Part II. , p. 35) - 39 
,, 7. Cervical vertebra of Plesiosaurus Hawkinsi, Owen, Lower 
Lias, Lyme Regis. (Guide Dep. Geol., Brit. Mus., 
Part II., p. 48) - - 39 
,, 8. Dapedius pholidoius, Ag., Lower Lias, Lyme Regis. 
(Guide Coll. Fossil Fishes, Brit. Mus., p. 29, 1888) 40 
., 0. Pholidophoms Bechei, Ag., Lower Lias, Lyme Regis. 
(Sir A. Geikie, Class Book of Geology, Ed. 2, p. 304) - 40 
,, 10. Teeth of Acrodus Anningice, Ag., Lower Lias, Lyme 
Regis. (Guide Coll. Fossil Fishes, Brit. Mus., p. 9) - 41 
,, 11. Dorsal spine of Hybodus, Lower Lias, Lyme Regis. 
(Guide Coll. Fossil Fishes, Brit. Mus., p. 9) - - 41 
,, 12. Ammonites planorbis, Sow., Lower Lias. (Geikie, Text- 
Book of Geology, Ed. 2, p. 790) - - 44 
,, 13. Ammonites angulatus, Schloth., Lower Lias. (After 
Wright) - - 44 
,, 14. Ammonites Bucklandi, Sow., Lower Lias. (After Wright) 44 
,, 15. Ammonites obtusus, Sow., Lower Lias. (Geikie, Text 
Book of Geology, Ed. 2, p, 790) 44 
,, 16. Ammonites oxynotus, Que'nst., Lower Lias. (After Wright) 44 
,, 17. Ammonites raricostatus, Ziet., Lower Lias. (After Wright) 47 
,, 18. Ammonites armatus, Sow., Lower Lias. (After Wright) - 47 
,, 19. Ammonites Jamesoni, Sow., Lower Lias. (Geikie, Text 
Book of Geology, Ed, 2, p. 791) . 47 
,, 20. Ammonites brevispina, Sow., Lower Lias. (Geikie, Text 
Book of Geology, Ed. 2, p. 791) . 47 
,, 21. Ammonites heterogencs, T. & B. , Lower Lias. (After 
Wright) - - .47 
,, 22. Belemnites clavatus, Blainv., Lower Lias. (After Phillips) 47 
,, 23. Ammonites striatus, Rein, Lower Lias. (Geikie, Class- 
Book of Geology, Ed. 2, p. 303) - 48 
,, 24. Ammonites Henleyi, Sow., Lower Lias. (After Wright) - 48 
,, 25. Ammonites Davosi, Sow., Lower Lias. (Geikie, Text-Book 
of Geology, Ed. 2, p. 791) 48 
26. Ammonites capricornus, Schloth., Lower Lias. (After 
Wright) - . 48 
,, 27. Pleurotomaria anglica, Sow., Lower and Middle Lias. 
(After Goldfuss) - . . 49 
,, 28. Lima gigantea, Sow., Lower Lias. (Geikie, Text- Book of 
Geology, Ed. 2, p. 776) - . 49 
,, 29. Jlippopodium ponderositm, Sow., Lower and Middle Lias. 
(Museum of Practical Geology) - 50 
