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PATAGONIAN EXPEDITIONS : PALAEONTOLOGY. 
GENERAL CONSIDERATIONS. 
The Patagonian Beds. 
History of Our Knowledge of the Patagonian Fauna. 
The first species of Invertebrates described from what is now known 
under the designation “ Patagonian beds ” is: Hypechinus patagonensis 
d’Orbigny (1842). Indeed, d' Orbigny has described, in the same publi- 
cation, other species from Patagonia, but most of them came from the 
northern parts of the country, and, as far as has been ascertained, do not 
belong to the true Patagonian beds. 
Darwin mentions in 1846 from the Patagonian beds a large oyster 
under the name of Ostrea patagonica, which is a mistake, this species be- 
ing different (O. ingens). In the same work, Sowerby (1846) gives de- 
scriptions and figures of 24 species from Santa Cruz, San Julian, and 
other localities, which undoubtedly belong to the Patagonian deposits. 
They are the following (corrected names in brackets) : 
1 . Terebratula patagonica ( Terebractella pi). 
2. Nucula glabra {Leda gi). 
3. Nucula ornata ( Malletia oi). 
4. CucullcBa alta. 
5. Trigonoccelia insolita ( Limopsis ii). 
6. Pecten geminatus. 
7. Pecten centralis. 
8 . Crass at ell a lyelli ( Crass ate llites li). 
9. Cardita patagonica. 
1 o. Cardium puelchum. 
1 1 . Venus meridionalis . 
12. Mactra (?) darwini. 
1 3 . Mactra rugata. 
14. Trochus collar is ( Gibbula Icevis). 
1 5 . Scalaria rugidosa. 
1 6. Crepidula gregaria. 
1 7. Natica solida (N. darwini). 
18. Turritella ambulacrum. 
19. Turritella patagonica. 
20. Struthiolaria ornata. 
21. Fusus noachinus (Siphonalia ni), 
22. Fusus patagonicus ( Trophon pi). 
23. Voluta alta ( ? ). 
24. Balanus varians. 
Including the large oyster mentioned by Darwin, these are 25 species, 
of which 22 are represented in our collection, and belong undoubtedly to 
the Patagonian beds. Of the remaining three, Leda glabra belongs here 
according to v. Ihering; Mactra rugata is very doubtful, and, although 
recorded from the typical locality at Santa Cruz, has never been found 
