PLATE I. 



Fig. 



1, a, b. Trigonia clavellata, Sow. Specimen of adult growth from the Lower Calcareous 



Grit of Weymouth. (Page 18.) 



2. ,, „ A smaller example from the same locality. 



3. „ Bathonica, Lye. Great Oolite Box, near Bath. (Page 17.) 



4, 5, 6. „ recticosta, Lye. Inferior Oolite, Cloughton, near Scarborough. 



(Page 16.) 



7. „ gemmaia, Lye. Inferior Oolite, Cheltenham. (Page 15.) 



8 and 10. „ duplicata, Sow. Inferior Oolite, near Stroud. (Page 14.) 

 9. „ „ Inferior Oolite, near Yeovil. (Page 14.) 



The small dimensions of British examples of the Scaphoidece (figs. 3 to 9 inclusive) have induced me 

 to subjoin a wood engraving of Trigonia navis, Lam., which is the typical species of that section, and 

 which exemplifies its peculiar features much more prominently than is seen in the British species. Our 



specimen, which is of adult growth, but not of the largest dimensions, is from the thick deposit of dark 

 clays at Gundershofen (Haut Rhin), which Professor Quenstedt has shown to belong to the lowest zone of 

 the Inferior Oolite in Southern Germany. Other localities for this species are Metz (Mozelle), Giinsberg 

 (Solothurn). For numerous figures, see Agassiz, ' Trigonies,' tab. i; also, Quenstedt, ' Der Jura,' tab. xliv, 

 fig. 13. 



