EXPLANATION OF PLATES. 443 



FlGirUE. PAGft. 



2. Triquetra avicularis, Lam. Brazil, .... 243 



3, 4. Prisodon ambigua, Lam. Brazil, .... 243 



5. Iridina (Leila) Blainvilliana, Lea. So. America, . 243 



6. J^theria Cailliaudi, Fer. River Nile, . . . .244 

 T. Bartlettia Stefanensis, Moric. Amazon River, . . 245 

 8. Iridina (Spatha) rubens, Lam. River Nile, . . 243 



Plate 125. 

 8, 9. Iridina (Haplothterns) capax, Conr. Pebas Group, 



Upper Amazon, 



243 

 236 

 244 

 244 

 244 

 243 



10. Anthracosia Lottneri, Ludw. Carboniferous, 



11. M3'cetopus soleniformis, d'Orb. So. America, 



12. 13. Solenaia emarginatus. Lea. Siam, 

 14, 15. Muilei'ia Guaduasiana, d'Orb. So. America, 

 16, 11. Arconaia contorta. Lea. China, . 



18. Trigonia pectinata, Lam. Australia. From a specimen 



in alcohol ; the gills slightly curled and contracted, 

 thej^ should terminate near the margin, between the 

 arrows which indicate the inhalent and exhalent cur- 

 rents ; a, a', adductors ; h I, ligament ; ^, t', dental 

 sockets; o, mouth ; I t, labial tentacles or palpi; p, 

 pallial line ; m, margin ; /", foot ; u, cloaca, . . 245 



19. Trigonia navis, Lara. Liassic ; Alsace, . . . 246 



20. Trigonia costata, Park. ^. Oolite ; Britain, . . 246 



21. Trigonia longa, Agass. Neocomian ; Neuchatel, . 246 



22. Trigonia Parkinsoni, Agass. Portlandian ; Besan^on, 246 



23. Trigonia scabra. Lam. Cretaceous ; France, . . 246 



24. Curtonotus elongatus, Salter. Devonian; England, . 241 



25. Palseoneilo Bedfordensis, Meek. (Cast.) Carb. ; Ohio, 250 



26. Yerticordia cardiformis, Wood. Crag, Suffolk, Eng., 191 



Plate 126. 



21. Nucula obliqua, Lam. Australia, .... 248 



28. Nucula (Acila) divaricata, Hinds. China Sea, . . 248 



29. Nucula (Acila) ornatissima, d'Orb, Cret.; Eur., . 248 



30. Ctenodonta Pectunculoides, Hall. L. Silur. ; Cincin- 



nati, Ohio, .260 



31. Leda pernula, Miiller. Boreal Seas, . . . . 248 



32. Leda (Adrana) Sowerbyana, d'Orb. Xipixapi, . . 249 



33. Yoldia myalls. Couth. United States, . . . 249 



34. Yoldia (Malletia) Chilensis, Desm. Yalparaiso, . . 249 



35. Yoldia (Neilo) Cumingii, A. Ad. (= Australis, Quoy). 



New Zealand, ........ 250 



36. Yoldia ( Nucularia) papyria, Conr. Cret.; N.Jersey, 250 

 31,38. Glyptarca primseva, Hicks. Silurian; Wales, . 255 

 39. Area Nose, Linn. Mediterranean, .... 252 



