ORTMANN : TERTIARY INVERTEBRATES. 309 



Mr. Hatcher's observations indicate the existence of such beds near San 

 Julian. He discovered marine beds unconformably overlying the Pata- 

 gonian beds at Darwin Station (Hatcher, 1900 a, p. 108). Here he col- 

 lected only two species : Ostrea patagonica and Trophon laciniatus var. 

 inornatus. The latter form most distinctly points to the Cape Fair- 

 weather beds, but the oyster is different. It is this the southernmost 

 locality at which the true O. patagonica has been found, and the associa- 

 tion of this Entrerios oyster with the Cape Fairweather Trophon suggests 

 very strongly that both deposits may be identical in age, and that their 

 difference may be due to their geographical location : then the Miocene 

 Patagonian Ostrea ingens would remain the identical species in Pliocene 

 times in the south, while it changes into O. patagonica in the Pliocene 

 farther north. 



It is not impossible that our locality at Darwin Station is identical with 

 one of the type localities of Ameghino for the marine Tehuelche beds. 

 V. Ihering (1897) mentions four species ( O. ferrarisi = patagonica, Pccten 

 actinodes, Scalaria rngulosa var. obsoleta, and Trophon variant = laciniatns 

 var. inornatus] from a locality between Santa Cruz and San Julian, which 

 he spells : Santa Rosa (pp. 225, 277, 296), Punta Rosa (p. 227) and Pta. 

 or P. Rasa (pp. 322 and 323). Since the latter form is given for the 

 same species, for which Santa or Punta Rosa is quoted, there is no doubt 

 that the same place is intended. Mr. Hatcher informs me that he has the 

 vague impression that the peninsula between the bay of San Julian and 

 the sea is called " Punta Raza" by the sailors. If that is true, it is very 

 probable that our locality at Darwin Station is not very far from, if not 

 identical with Ameghino's Punta Rasa, since it is situated near the base 

 of this peninsula. Punta Rasa is said to represent "Tehuelche" beds, 

 and of the four species mentioned by v. Ihering, we possess 2 from Dar- 

 win Station (Ostrea patagonica and Trophon inornatus], and 2 from Cape 

 Fairweather (Pecten actinodes and Trophon inornatus}. This fact also is 

 much in favor of the view that Hatcher's locality at Darwin Station as 

 well as the Cape Fairweather beds belongs to the same horizon as v. 

 Ihering's and Ameghino's Punta Rasa. 



Another locality, which corresponds stratigraphically with the Cape 

 Fairweather beds, has been discovered by Mr. Hatcher at Lake Pueyr- 

 redon, where marine beds again overly the Santacruzian beds, and cap 

 the whole "Rio Tarde section" (Hatcher, 1900 a, p. 108). Only two 



