FROM THE WEST COAST OF AFRICA. 



153 



fig. 2 ; and fig. 5 as fig. 4. The full front view of a complete 

 frustule of A. Africanus shown in fig. 8, is again unlike what would 

 be expected from the three-quarter view of it shown in fig. 3. 



DESCRIPTION OF PLATE XII. 



Fig. 1. Aulacodi setts Africanus, side view, a large specimen. 



2. Ditto „ a small specimen. 



3. Ditto on its edge. 

 8. Ditto front view. 



4. Atdacodiscus Kittoni (recent) New Zealand. 



5. Ditto on its edge. 



6. Ditto (Fossil) Mexillones deposit, Bolivia. 



7. Aulaco discus Johnsonii. Algoa Bay Guano, 

 (a) Process broken off. 



All the figures are drawn to a scale of 400 diameters. 



