Raymond: Pelecypoda of Chazy Formation. 343 



6, Clenodonla diibiaformis Raymond. Natural size. 



7, 8. Clenodonla patvidens Raymond. The interior of one specimen and ex- 

 terior of another. Natural size. 



9. Clidophorus obscurus Raymond. Tlie type, natural size. 



ID, II. Vaniixcfnia limbala Raymond. Two right v^alves, natural size. 



12, 13. Sowleria canadensis (Raymond). Two right valves, natural size. 



14. Cyrlodonta scala Raymond. A right valve, natural size. 



15. Cyrlodonla solilaria Raymond. The only known specimen, natural size. 



16. Cyrlodonla lamellosa "Hudson. The left valve of a complete individual. X 2. 



17. Cyrlodonla breviiiscula Billings. The type. X 2. 



18. 19, 20. Clionychia monlrealensis (Billings). The types, natural size. 



21, 22, 23, 24. The same species. Specimens from Valcour Island, natural size. 

 25, 26. Clionychia marginalis Raymond. The holotype, natural size. 

 27, 28. Ambonychia ? ciirvala Raymond. A left valve, natural size. 



Plate XXX. 



I, 2, 3. Ambonychia ? ctirvala Raymond. The cotypes, natural size. 



4, 5. Conocardiiim beecheri Raymond. A left and a right valve. X 4. 

 6, 7. The same species. Two left valves. X 2. 



8, 9, 10. The same species. A specimen retaining both valves. X 6. 



II. Modiolopsis exanimis Raymond. A right valve, natural size. 



12, 13. Modiolopsis fabaformis Kaymond. A left and a right valve, natural size. 



14. Modiolopsis parviuscula Billings. The type, natural size. 



15, 16. IModiolopsis parviuscula, Billings. A specimen supposed to be this 

 species, natural size. 



17, 18, 19. Endodesma Iransceps Raymond. Two right valves and one left 

 valve, natural size. 



20. Whileavesia ? expansa Raymond. An imperfect left valve, natural size. 



21, 22. Modiolopsis sowleri Raymond. An internal cast, and a cast of the 

 exterior of a right valve, natural size. 



23. 24. Whileavsia ? undala Raymond. A left valve, natural size. 



