ORTMANN : TERTIARY INVERTEBRATES. 277 



At the same locality 100-150' below the fossils mentioned above, have 

 been found Mammalian bones associated with Leda errazurizi(>}. 

 Shell Gap, Rio Chico, lower horizon. 



Toxopneustes praecursor. L & S * Ostrea ingens. 



Cellaria fistulosa. J & S *Pecten geminatus. 



The list is too small to permit any conclusions. Toxopneustes pre- 

 cursor is also from the lowermost beds of the marine series at San Julian. 

 Shell Gap, Rio Chico, iipper horizon; 150-200' above lower horizon. 



J Scntella patagonensis. * Venus volckmanni ( ?). Galerus araucanus. 



J *Rhynchonella plicigcra. * Tellina tehuelcha. Vermetus cf. intortus. 



*Terebratella dorsata. *Mactra danvini. S * Struthiolaria ameghinoi. 



J * Terebratella patagonica. *Martesia patagonica. Balanus varians. 



P * Cardium puelchum ( ? ). *Gibbula dalli. 



* Venus meridionalis ( ? ). * Infundibulum corrugatum. 



Of these 16 species, 12 have been found at Santa Cruz. 4 are charac- 

 teristic Patagonian (mostly Juliense) fossils, while one is Suprapatagonian. 

 This locality offers in matrix, etc., a striking resemblance to that of the 

 upper Rio Chalia and 30 miles north of it, and 6 of the species have also 

 been found there. Petrographically and stratigraphically, these beds 

 would belong near the top of the series, while palaeontological evidence 

 points partly to the identity with the beds of the upper Rio Chalia, partly 

 to a lower position, near the base of the series. 



Mayer basin; upper Lignites, below Patagonian beds. 



Ostrea ingens has been found here, and indeterminable remains of 

 other Bivalves, possibly of a Mytihts. 



Arroyo Gio ; ca. 100 feet marine beds, between barren Cretaceous 

 sandstones and Santacruzian beds ; sandy facies. 



Heteropora pelliculata. * Cardium philippii (?). Crucibulum dubium. 



*Leda oxyrhyncha. * Cardium pisum. * Crepidula gregaria. 



*Leda errazurizi. S *Dosinia meridionalis. L *Turritella ambulacrum. 



S * Area patagonica. * Tellina jeguaensis. * Valuta g racilior. 



* Glycimeris ibari. *Psammobia patagonica. *Bulla patagonica. 

 L&- S* Ostrea ingens. S Dentalium octocostellatum. 



J& S *Pt>cten geminatus. * Gibbula dalli. 



Casts of indeterminable species of Natica, Marginella and Bivalves. 



