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. 
Toxopnenstes prae Cursor. 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 , upper horizon ; 150-200' above lower horizon. 
J Scutella patagonensis. 
J * Rhyne ho nella plicigera. 
* Terebratella dorsata. 
J * Terebratella patagonica. 
P * Car din rn puelchum ( ? ). 
* Venus meridionalis ( ? ). 
* Venus volckmanni (?). 
* Tellina tehuelcha. 
*Mactra darwini. 
* Martesia patagonica. 
* Gibbula dalli. 
* Infundibulum corrugatum. 
Galerus araucanus. 
Vermetus cf. intortus. 
S * Struthiolaria ameghinoi. 
Balanus varians. 
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 Mytilus. 
Arroyo Gio ; ca. 100 feet marine beds, between barren Cretaceous 
sandstones and Santacruzian beds ; sandy facies. 
Heteropora pelliculata. 
* Leda oxyrhyncha. 
* Leda errazurizi. 
S *Arca patagonica. 
* Glycimeris ibari. 
L & S* Ostrea ingens. 
J & S *Pecten geminatus . 
* Cardium pliilippii ( ? ). 
* Cardium pisum. 
S *Dosinia meridionalis. 
* Tellina jeguaensis. 
* Psammobia patagonica. 
S Dentalium octocostellatum. 
* Gibbula dalli. 
Crucibulum dubium. 
* Crepidula gregaria. 
L * Turrit ell a ambulacrum. 
* Voluta gracilior. 
* Bulla patagonica. 
Casts of indeterminable species of Natica, Marginella and Bivalves. 
