ORTMANN I TERTIARY INVERTEBRATES. 
307 
This would make the Magellanian beds Oligocene in age. 
The Cape Fairweather Beds (? Marine Tehuelche Beds). 
The Cape Fairweather beds were first described by Hatcher (1897 a, p. 
342). They are of marine origin, and their stratigraphical position is un- 
conformably on top of the Santacruzian beds (see section, 1. c., p. 344) : 
this separates them at once stratigraphically from the Patagonian beds, 
which are below the Santacruzian beds. 
A first, preliminary account of the fauna of these beds has been given 
by Pilsbry (1897 a). Further investigations have increased the number of 
species, and have made necessary a few corrections, so that the list of 
species known from the Cape Fairweather beds stands at present as 
follows : 
Relations and Distribution. 
1. Terebratella gigantea Mutation of T. patagonica, Patagonian beds. 
2. Ostrea ingens Patagonian beds. 
3. Pecten actinodes Mutation of P. geminaius, Patagonian beds; distribution north- 
ward from San Julian, in the Tehuelche beds (v. Ih.). 
4. Mytilus cf. chorus Patagonian beds and Recent (Chili). 
5. Meretrix rostrata Recent (Brazil and Uruguay). 
6. Dosinia meridionalis Patagonian beds and Entrerios beds (v. Ih.). 
7. Panop ea pilsbry i. 
8. Galerus mamillaris Recent, Chili to California. 
9. Crepidula dilatata Recent, southern Patagonia. 
10. Turritella innotabilis Mutation of T. patagonica, Patagonian beds; closely allied to 
T. cingulatiformis , Pliocene, Chili. 
11. Trophon laciniatus Mutation of T. patagonicus, Patagonian beds; Recent, Pata- 
gonia. 
T. 1. var. inornatus also at Darwin Station; Tehuelche beds (T. varians v. Ih.). 
12. Balanus cf. psittacus Patagonian beds, and Recent, Patagonia. 
13. Balanus cf. trigonus Recent, almost Cosmopolitan (Patagonia). 
14. Balanus Icevis Pliocene, Chili; recent, Patagonia, Chili to California. 
Indeterminable remains of Pinna , Area , Lucina (or Diplodonta ?), 
Cardita. % 
Of these 14 species, 4 ( Ostrea ingens , Mytilus chorus , Dosinia nierid- 
ionalis , Balanus psittacus ) are also represented in the Patagonian beds, 
while we may consider 4 others ( Terebratella gigantea , Pecten actinodes , 
Turritella innotabilis , Trophon laciniatus ) as mutations of Patagonian 
