SUPPLEMENT, PLATE XL 

 Fio. 



1, 2 Skcnidii/m Lewmi, var. Woodlandiense, Dav. Middle Llandovery, Wood- 



land Point, Girvan District. Coll. of Mrs. 

 R. Gray. \a,b. Enlarged. (P. 174.) 



3 — 5. „ Gratia, Dav. 3. Middle Caradoc, Thraive, Ayrshire. 4. Liternal 



cast of ventral valve. 5. Interior of valve 

 taken in gutta percha from the cast (P. 175.) 



6, 7. ,) -^ S/ialJockiense, Dav, Middle Caradoc, Shallock Mill, Ayrshire. 



6. A ventral valve, nat. size. 6 a, b, c. En- 

 larged. 7. Another smaller ventral valve. 

 Coll. of Mrs. R. Gray. (P. 174.) 



8 — 11. Orthis Ilirmanfensis, M'Coy. Caradoc shales above Herraant limestone, 



Aber Hermant, near Bala. 10, 11. Internal 

 cast of ventral valve. (P. 189.) 



12. „ Jdonia, Sow. Caradoc, Gelli Goin, near Bala. Coll. of Mr. J. 



Parrott. (P. 190.) 



13, 14. ,. Philipi, Dav.~ Cnradoc, Ty-isaaf, LlansantfFraid, Wales. 13. Ex- 



terior. 13 a. Enlarged. \2, b. Fragment of 

 shell enlarged. 14. Internal cast of dorsal 

 valve. 14 a. Interior of same valve taken 

 from the cast by means of gutta percha, 

 enlarged. Coll. of Mr. C. Croft, of Man- 

 chester. (P. 188.) 



1,5, 16. ,, Jonesi, Dav. 15. Impression or cast of the exterior of dorsal valve. 



15 a. The same enlarged. 16. Dorsal valve 

 and beak and area of ventral valve, enlarged. 

 (P. 190.) 



17 — 19. ,, Rankini, Dav. Llandeilo, Arduiillan Brae, Ayrshire. Coll. of Mrs. 



R. Gray. 17,17a. Exterior of dorsal valve. 

 18. Internal cast of dorsal valve. 18 a. 

 Portion of same enlarged. 19. Internal cast 

 of ventral valve. (P. 190.) 



20,21. SlropJiomena SJiaUockiensis,J)?iV. 20. Exterior. 21. Interior of ventral valve. 



Upper Caradoc or Bala Schists, Trystion 

 Valley, near Cynvvyd, North Wales, at the 

 foot of Moel Ferna, Bervvyn mountains. Coll. 

 of Mr. J. Parrott. (P. 192.) 



22. ,, c/randis. Sow. Interior of dorsal valve, enlarged, taken from an 



internal cast found by Dr. C. Callaway in the 

 Caradoc at Marsh Brook, Shropshire. (P. 

 195.) 



23. Rht/nchonella Balclefchiensis, Dav. Llandeilo, Minuntion, Ayrshire. Coll. of 



Mrs. R. Gray. 23 a, b, c. Enlarged. (P. 200.) 



24. ,, ?iucula, var. ? Llandeilo, Minuntion, Ayrshire. Coll. of Mrs. 



R.Gray. 24 a. Enlarged. (P. 201.) 



25. „ Feachi, Dav. Llandeilo, Craighead, Girvan. Coll. of Mrs. R. 



Gray. (P. 201.) 



26. „ Scofica, Dav. Llandeilo, Craighead, Ayrshire. Coll. of Mrs. 



R. Gray. 26 a, b, c, d. Enlarged. 26. Seen 

 from the beaks to show septum (s) on both 

 valves. (P. 201.) 



27. „ deceiiipUcafa, Sow. Lower Llandovery, Mullock Hill beds of 



Thraive Glen. 27 a. Enlarged. Coll. of 

 Mrs. R. Gray. (Pp. 151, 202.) 



28. Leptana ienuicincta, M'Coy. External cast of ventral valve seen from the 



beak, enlarged. Llandeilo, Ayrshire. (P. 168.) 



