PLATE I. 



Fig. Page 



1. Sinuites anceps (Salter MS.). Side view. X 1^. Middle Bala, Hor- 



derley. Mas. Pract. Geol. [28025]. 5. 



la. Dorsal view. X 1|. l/>. Front view, x 1^. 



2. Ditto. Internal cast. Side view. X 1|. Same horizon and locality. 



Mus. Pract. Geol. [28027]. 5. 



2a. Dorsal view. X 1^. 



3. Ditto. Internal cast. Dorsal view. X 1^. Bala Series, Soudley 



Quarry. Sedgwick Mus. 5. 



4. Sinuites balclatchieiisis, sp. nov. Internal cast with portion of shell pre- 



served. Side view. X 1^. Balclatchie Group, Balclatchie. Mrs. 

 Gray's Coll. 6. 



4a. Front view. X 1^. 



5. Ditto. Side view of internal cast, showing transverse groove. X 1 ^. 



Same horizon, locality and collection. 6. 



6a. Sinus view. X 1^. 



6. Ditto. Dorsal view. X 1^. Same horizon, locality and collection. 6. 



7. Ditto. Restored outline of sinus view. X 1^. 6. 



8. Sinuites bilobatus (Sow.). Side view of ty])e. Nat, size. Middle Bala, 



Horderley. Mus. Pract. Geol. [G850]. 7. 



8a. Sinus view. Nat. size. 81). Front view. Nat. size. 



9. Sinuites discoides, sp. nov. Internal cast. Side view. X 2. Balclatchie 



Group, Ardmillan. Mrs. Gray's Coll. 9. 



da. Dorsal view. X 2. 9I>. Ornament. X 20. 



10. Ditto. Internal cast. Side view. X 2. Same horizon, locality and 



collection. 9. 



11. Ditto ?. Internal cast. Side view. X 2. Same horizon, locality and 



collection. 9. 



lift. Dorsal view, x 2. 



12. Sinuites eloiujatns (Portl.). Internal cast. Side view of supposed type. 



X 11 Bala Series, Tyrone. Mus. Pract. Geol. [27990]. 9. 



12a. Sinus view. X Ij. 



13. Ditto. Side view, showing ornament. X 1^. Same horizon, locality 



and collection [27991]. 9. 



13a. Portion of ornament. X 10. 



14. Ditto ?. Internal cast. Side view. x 1^. Starfish Bed, Thraive 



Glen, Girvan. Mrs. Gray's Coll. 10. 



