480 Ortmann — Some new marine Tertiary horizons. 



(Ost? i eap., Zucinap.f, and Crepidula g.). Thus it seems — 

 although the number of fossils is quite small — that the identity 

 of our fifth horizon with the Suprapatagonian beds is war- 

 ranted, especially, if we take into consideration that some of 

 the species (Ostrea, Pectuncidus, Crepidula) are very charac- 

 teristic forms of these deposits. 



In the oyster bed " below V " only oysters of the type of 

 0. philippii are found: a single upper valve from the same 

 bed suggests also the presence of 0. hatcheri Ortm.,** but this 

 valve is not sufficient to make the identification certain. 



The beds discussed above are separated from the third hori- 

 zon by the coal underlying the fifth horizon and its subdi- 

 visions. The third horizon contains the following fossils : 



Ostrea torresi Phil, (abundant). 



Cardita spec. nov. 



Venus spec. nov. (No. 1) (also in horizon II). 



Venus spec. nov. (No. 2). 



Cytherea (?) spec. nov. 



Glycimeris spec nov. 



Patella spec. nov.\ 



Trochus ( Calliostoma) spec. nov. 



Trochita costellata Phil, (also in horizon II). 



Natica chiloensis Phil, (also in horizon II). 



The difference of this fauna from that of horizon V is very 

 striking. None of the species has been found in Patagonia, 

 and most of them are new to science. Ostrea torresi is the 

 only one previously recorded from this locality, and it is the 

 only abundant form, the others being much rarer. Trochita 

 costellata has been recorded from Lebu, Chile, and Natica 

 chiloensis from the island of Chiloe, both localities being 

 regarded as of the age of the "Navidad Stufe" of Steinmann.:): 

 The latter two species as well as Venus spec. nov. (No. 1) are 

 also represented in the second horizon. 



The second horizon, the lowermost in the series containing 

 marine fossils, has yielded the following species : 



Ostrea sp. f (only upper valves). 

 Venus spec. nov. (= No. 1) (also in horizon III). 

 Dosinia complanata (Phil.) 

 Glycimeris ibari (Phil.) 

 Lutraria spec. nov. 

 Turritella spec. nov. (very abundant). 

 Trochita costellata Phil, (also in horizon III). 



*See 1. c, p. 355, pi. 11, fig. 1 (= 0. percrassa v. lb., 1. c , p. 221). 

 \ Or Acmcea spec. nov. 



% See Philippi, 1. c. p. 249 and 250; Steinmann and Moericke, in Neues Jahr- 

 buch f. Miner., etc , Beil. x, p. 593, 1896. 



