266 



PATAGONIAN EXPEDITIONS '. PALAEONTOLOGY. 



"Patagoniany^r;//c?//b;/," and Ameghino subdivides this into a lower part, 

 " Piso Juliense," and an upper part, " Piso Leonense." The upper division 

 he calls by the name of "Suprapatagonian " beds, and separates it from the 

 Patagonian formation, making it a subdivision, "Piso Suprapatagonico," 

 of the Santacruzian formation. V. Ihering follows him in this arrange- 

 ment, and gives "Santacruzian formation" as the horizon for all marine 

 "Suprapatagonian" fossils. (It is well to bear in mind that v. Ihering's 

 "Santacruzian" means the same as Ameghino's "Suprapatagonian.") 



As Hatcher (1900 a, p. 99, ff., and i9Oob, p. 263, ff.) has repeatedly indi- 

 cated in his preliminary publications, he has failed entirely to verify these 

 subdivisions of the marine beds underlying the typical (non-marine) San- 

 tacruzian beds, and he was unable to find any stratigraphical evidence for 

 them, and I shall endeavor here to show that the palczontological material 

 collected also fails to warrant any subdivisions of this marine series. 



In order to demonstrate this, we must choose the type-locality at the 

 mouth of the Santa Cruz river and its fauna as a starting point. Accord- 

 ing to Hatcher (1900 b), the deposits at this locality consist of several 

 hundred feet of soft sand and clays, often filled with hard concretions, 

 and interrupted occasionally by a stratum of hard sandstone. The fossils 

 are found both in the loose material and in the harder concretions. 



The following is the list of all fossils recorded from this locality : 



1 . Cidaris antarctica. 



2. Schiz aster ameghinoi. 



3. Aspidostoma giganteum. 



4. Reticulipora patagonica. 



5. Tennysonia subcylindrica. 



6. Rhynchonella plicigcra (v. Ih.). 



7. Terebratella dorsata var. 



8. Terebratella patagonica. 



9. Nucnla patagonica. 



10. Nucula reticularis. 



11. Leda glabra (Sow., v. Ih.). 



1 2. Leda oxyrhyncha. 



13. Leda errazurizi. 



14. Malletia ornata. 



15. Cucullcea a/ fa. 



1 6. Cucullcea darwini. 



17. Limopsis insolita. 



1 8. Area patagonica. 



19. Glycimeris ibari. 



20. Pcrna quadrisulcata. 



2 1 . Ostrea ingens. 



22. Pec ten proximus. 



23. Pecten prcemmcius. 



24. Pecten geminatns. 



25. Pinna semi'costata (v. Ih.). 



26. Mytilus cf. chorus (v. Ih.). 



27. Crassatellites lyelli. 



28. Crassatellites kokeni. 



29. Crassatellites quartns. 



30. Cardita elegantoides. 



3 1 . Cardita inaqualis. 



3 2 . Cardita patagonica. 

 3 3 . Litcina promaitcana. 

 34. Lvcina ortmanni. 

 3 5 . Cardium philippii. 



36. Cardium puclclnnn. 



37. Cardium pisinii. 



38. Amathusia angnlata. 



