PLATE II. 



Fig. 1. — Lithodomiis linf/HaUs. A rare form from the Limestone of AVenslejdale. In the 

 Geological Collection of the Tork Museum. (Page 7-±.) 



Fig. 2. — Litliodomus liiu/ualis. A cast showing anterior and posterior adductor muscle-scars from 

 Wensieydale. In the same Collection. (Page 74.) 



Fig. 3. — LitJiodoinus lingunlis. A medium sized example from East Kelbride. In the Braidwood 

 Collection of Dr. Hunter. (Page 74.) 



Fig. 4. — Litliodomus linqualis. A perfect specimen. In the Gilbertson Collection, now in the 

 British Museum (Nat. Hist.). (Page 74.) 



Fig. 5. — Modiola mec/aloha. A left valve with the test preserved from the Coombe3 Limestone, 

 Ecdesdale. Collected by Mr. J. Dunn. (Page 60.) 



Fig. 6. — Modiola megaloha. Another example from the same locality. (Page 60.) 



Fig. 7. — Modiola megaloha. A larger example from the same locality, with the test partially 

 preserved, but showing the posterior adductor muscle-scar. (Page 60.) 



Fig. 8. — Modiola megaloha. A specimen of a left valve, showing portions of the hinge-plate, 

 pallial line, and interior. Same locality. (Page 60.) 



Fig. 9. — Modiola megaloha. A specimen showing the anterior adductor muscle-scar. (Page 60.) 



Fig. 10. — Modiola megaloha. A cast of the interior of both valves. Tiie original of Baily'a 

 Mgalina Foynesiana, from Foynes Island, showing pallial line, adductor scars, and the absence of a 

 striated hinge-plate. lu the Collection of the Irish Greological Survey. (Page 60.) 



Fig. 11. — Modiola transversa. An almost perfect example from the Toredale shales of Congleton 

 Edge. My Collectiou. (Page 67.) 



Fig. 12. — Modiola transversa. The cast of a left valve. Showing anterior and posterior adductor 

 muscle-scars. Same locality. My Collection. (Page 67.) 



Fig. 13. — Modiola emaciata. From the Carboniferous Limestone of Wensleydale, left valve. 

 In the Geological Collection of the Manchester Museum, Ouens College. (Page 68.) 



Fig. 14. — Litliodomus carhonarius. The interior of a left valve, showing the hinge-line from the 

 Calciferous Sandstone series, Randerstone, Fife. In the Collection of Mr. J. Kirkby, of Leven. 

 (Page 80.) 



Fig. 15. — Litlionomus carhonarius. A partly decorticated example of a right valve on same slab 

 as tiie preceding. (Page 80.) 



Fig. 16. — Litliodomus carhonarius. A large example from the same localitv. My Collection. 

 (Page 80.) 



Fig. 17. — Litliodomus carhonarius. Both valves, showing well-[ireserved test and periostracum. 

 Carboniferous shales of Eskdale. My Collection. (Page 80.) 



Fig. 18. — Litliodomus carhonarius. Another example from the same locality. My Collection. 

 (Page 80.) 



Fig. 19. — Litliodomus carhonarius. — From a slab containing very numerous examples, to show the 

 form of young specimens. Same locality. My Collection. (Page 80.) 



Fig. 20. — Modiola Macadamii. The original of Portlock's M. Macadamii, var, angusta. From the 

 Collection of the Geological Survey, Jermyn Street. (Page 63.) 



Figs. 21 and 22. — Modiola Macadamii. Other small examples from the same slab. (Page 63.) 



Fig. 23. — Modiola lata. The interior of a very poor example from Cultra, Co. Down. My 

 Collection. (Page 65 ) 



Fig. 24. — Modiola lata. — The cast of a left valve showing anterior adductor muscle-scar and an 

 oblique groove passing from the umbo to the lower margni. Portlock's Collection in the Geol. 

 Survey Museum. (Page 65.) 



Fig. 25. — Modiola lata. The original of Modiola Macadamii, var. lata, from Ballynascreen, 

 partially decorticated. In the same Collection. (Page 65.) 



Fig. 26. — Modiola lata. A testiferous example of a left valve. The original of M. Macadamii, 

 var. elongata. In the same Collection, on the same slab as the preceding. (Page 65.) 



Fig. 27. — Modiola lata. The anterior portion of the cast of the interior of a left valve showing 

 the anterior adductor scar on the same slab as the preceding. (Page 65.) 



