PLATE II. 



Fig. 



1. Membranipora tuberculata, p. 30. 



a. Portion with the tubercles distinct, magnified 25 diameters. 

 I. Ditto magnified 50 diameters. 



c. Portion with the tubercles worn off or absent, magnified 25 diameters. 



d. Ditto magnified 50 diameters. 



2. M. monostacJiys, p. 31 ; magnified 25 diameters. 



3. M. oblotif/a, p. 34. 



a, a, a". Magnified 25 diameters. 



b, 1) . Magnified 50 diameters. 



4. M. biclens, p. 34. 



a, c, e. Magnified 25 diameters. 



b, d. Magnified 50 diameters. 



5. M. andegavensis, p. 34. 



a. Magnified 25 diameters. 



b. Magnified 50 diameters. 



6. M. Savartii, p. 31. 



a. Magnified 25 diameters. 



b. Magnified 50 diameters. 



7. Biflustra delicatulu (older or worn condition), p. 72. 



a. Natural size of fragment. 



b. Portion, magnified 25 diameters. 



c. Longitudinal section. 



d. Horizontal section. 



8. Eschara monil/fera (?) (back view of broken fragment). 



9. Membranipora andegavensis (older state). 



c. Front, magnified 25 diameters. 



d. Back of detached portion, magnified 25 diameters. 



