308 PATAGONIAN EXPEDITIONS : PALAEONTOLOGY. 



forms. On the other hand, we have in 5 species (Meretrix rostrata, 

 Galerus mainillaris, Crepidula dilatata, Balanus trigonus, Balanus Icevis] 

 new elements in this fauna, and it is very significant that these are all still 

 living species. This introduction of new, recent elements into the Cape 

 Fairweather fauna, as compared with the Patagonian, is the most impor- 

 tant character, agreeing completely with the stratigraphical position. 



Altogether, the Cape Fairweather fauna contains 8 living species (57 

 per cent.), 5 of which are still found in Patagonia (Crepidula dilatata, 

 Trophon laciniatus, Balanus psittaciis, B alarms trigomis, Balamis lcems], 

 while 2 are found in Chili (Mytilus chorus and Galerus mamillaris), and 

 i in Uruguay (Meretrix rostrata}. This fact approximates this fauna so 

 closely to the recent one, that we may safely regard the Cape Fairweather 

 beds as Pliocene. 



Only a few members of this fauna have been found elsewhere. Pecten 

 actinodes was recorded long ago from various localities in Patagonia 

 (chiefly the northern part), and has been given by v. Ihering (according 

 to Ameghino's material) for the Tehuelche formation. The same is true 

 in the case of Trophon laciniatus var. inornatus, which is mentioned by 

 v. Ihering (as Trophon varians] from the Tehuelche beds (see below). 

 Dosinia meridionalis has been recorded (aside from the Patagonian beds) 

 from the Entrerios beds, and Turritella innotabilis finds a closely allied 

 form in the Pliocene T. cigulatiformis of Chili. Thus it would seem, that 

 the Pliocene Coquimbo beds of Chili, the Entrerios beds of Parana, and 

 the "Tehuelche" beds are in some degree correlated with the Cape 

 Fairweather beds.. But since a large number of Coquimbo- and Entrerios- 

 species are known (Philippi, Mcericke, v. Ihering), the above relations are 

 not satisfactory, and if these beds are really contemporaneous, we should 

 expect a larger number of affinities. 



On the other hand, we must take into account the much more southern 

 location of the Cape Fairweather beds than any of the other beds, and if 

 they all really belong to the Pliocene, we should expect considerable 

 climatic differences in their fauna. 



For the present it is impossible to say, whether the few relations on the 

 one side, and the differences on the other, indicate a difference in age, or 

 a difference in geographical position. The solution of this question may 

 be obtained by a closer examination of corresponding beds in the north- 

 ern parts of Patagonia (from San Julian northward to Entrerios) : we 

 have numerous indications that such beds really exist there. 



