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PATAGONIAN EXPEDITIONS ! PALAEONTOLOGY. 
The Navidad beds of Chili are undoubtedly the best known Tertiary 
deposits of the southern hemisphere, at least as regards their Palaeontol- 
ogy, and Darwin, d’Orbigny, Philippi, and Moericke held the opinion that 
they are about contemporaneous with the Patagonian beds. 
According to our collections, the following Navidad fossils have been 
found in the Patagonian beds : 
A. Identical species : 
Leda oxyrhyncha. 
Leda errazurizi. 
Limopsis insolita. 
Gly rimer is ibari ( ? ). 
Mytilus cf. chorus ( ? ). 
Cardita volckmanni. 
Lucina promaucana. 
Amathusia angulata. 
Venus cliiloensis. 
Venus meridionalis. 
Venus volckmanni. 
Venus navidadis. 
Dentalium sulcostmi. 
Gibbula leans. 
Scalaria rugulosa. 
Galerus araucanus. 
Crepidula gregaria. 
Nalica ovoidea. 
Natica secunda. 
Natica darivini. 
Turritella ambulacrum. 
Turritella breantiana. 
Turritella patagonica . 
Aporrhais araucana. 
Pyrula Carolina. 
Buccinum obesum minor. 
Siphonalia domeykoana. 
Voluta triplicata. 
Valuta domeykoana. 
Cancellaria medince ( ? ). 
Terebra costellata. 
Pleurotoma subcequalis. 
B alarms cf. psittacus ( ? ). 
Balanus varians. 
B. Closely allied species are the following: 
Schizaster ameghinoi . . . 
Nucula patagonica . . . 
Malletia ornata 
Cucullcea alia 
Area patagonica 
Pecten proximus 
Cardium philippii 
Cardium pisum 
Tellina jeguaensis .... 
Mactra garretti 
Sigapatella americana . 
Struthiolaria ameghinoi 
Tritonium morgani 
Urosalpinx elegans 
Fusus torosus 
S. valdivianus. 
N. araucana. 
M. volckmanni. 
C. chilensis. 
A. oxytropis. 
P. caracolensis. 
C. multiradiatum. 
C. spheeridium. 
T. promaucana. 
M. truncatula. 
S. colchaguensis. 
S. chilensis. 
T. verruculosum. 
U. leucostomoides. 
F. pyruliformis. 
Thus, out of 15 1 species, 34 are identical with species found in the 
Navidad beds, that is to say, 22 per cent, or almost one quarter. This 
is certainly to be regarded as a high percentage, considering the consid- 
erably more northern situation of the Navidad beds, and undoubtedly 
