PLATE IV. 



Fig. 1. — Pinna JidhcUifurnm. The specimen described as P. fiahpUifin-rnU, 

 var. inseqnicostata, by Portlock. From Carnteel, Tyrone. (Page 1.) 



Fig. 2,.—Leiopferia Thomjwoni. The cast of a left valve. From Potmetal 

 Plantation, Fife. In the Collection of the Geological Survey, Jermyn Street. 

 (Page 17.) 



Fig. 3. — Leiopteria Thompsoni. A more perfect specimen of the cast of a left 

 valve, showing the anterior hinge-teeth. Same locality and Collection. (Page 1 7.) 



Fig. 4. — Lelopfrrid lunnlafa. The type of AincnJa anriiiatd, M'Coy. From 

 Eohan Bay, Dnnkineely, co. Donegal, Ireland. In the Griihth Collection, Museum 

 of Science and Art, Dublin. (Page 11.) 



Fig. 5. — Lrlopfrria Junuhitn. Portion of the cast of a left valve, the type of 

 M'Coy's Acicvln iiifonn'ni. From Killogunra, Killalu, co. Mayo. Same Collection. 

 (Page 11.) 



Fig. (3. — Leloptrrid laminosa. The cast of a small specimen of the left valve. 

 From Castleton, Derbyshire. My Collection. (Page 14.) 



Fig. 7. — Tjpioptcria Thompsoni. A young example of the right valve, with the 

 test. Same locality and Collection. (Page 17.) 



Fig. 8. — Lrioptrrla lunuhita. A young example of the left valve. Same 

 locality and Collection. (Page 11.) 



Fig. 9. — Adinopteria pcr^ivlrafa. The type specimen, figured by M'Coy. 

 From Lowick. In the Collection of the Woodwardian Museum, Cambridge. 

 (Page 23.) 



Fig. 10. — Artlnopfpria pevsulcaia. A fine bivalve example. From the Lime- 

 stone of Eskerhouse, near Grassington. In the Collection of the Geological 

 Survey, Jermyn Street. (Page 23.) 



Fig. 10 a. — Adinopteria persulcata. The same specimen, viewed from the front. 



Fig. 11. — Adinopteria. prrsvlcata. From the LoAver Limestone series at 

 Lesmahagow, near Glasgow. Same Collection. (Page 23.) 



Fig. 12. — Leiopteria Thompsoni. — The type of Pteriiiea Thonip.^oni, Portlock. 

 From CO. Fermanagh. Same Collection. (Page 17.) 



Fig. 13. — Leiopteria Thompsoni. A second specimen. Same locality and 

 Collection. (Page 17.) 



Fig. 14. — Tjciopferia Jonr/irostris. A left valve. From Black Limestone above 

 the massif of White Limestone, below Mam Tor, Castleton. My Collection. 

 (Page 20.) 



Fig. 1-5. — Leiopteria loni/irostris. Another specimen. Same locality and 

 Collection. (Page 20.) 



