298 PATAGONIAN EXPEDITIONS : PALEONTOLOGY. 



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. Dentalium sulcosum. Aporrhais araucana. 



Leda errazurizi. Gibbula lavis. Pyrula Carolina. 



Limopsis insolita. Scalaria rugulosa. Buccinum obcsum minor. 



Glycimeris ibari ( ? ). Galerus araiicanus. Siphonalia domeykoana. 



Mytilus cf. chorus ( ? ). Crepidula gregaria. Valuta triplicata. 



Cardita volckmanni. Natica ovoidea. Valuta domeykoana. 



Lucina promaucana. Natica secunda. Cancellaria medina ( ? ). 



Amathusia angulata. Natica darwini. Terebra costellata. 



Venus chiloensis. Turritella ambulacrum. Pleurotoma subczqualis. 



Venus meridionalis. Turritella breantiana. Balanus cf. psittacus ( ? ). 



Venus volckmanni. Turritella patagonica. Balanus varians. 

 Venus navidadis. 



B. Closely allied species are the following : 



Schizaster ameghinoi S. valdivianus. 



Nucula patagonica .TV. araucana. 



Malletia ornata M. volckmanni. 



Cucullcea alta C. chilensis. 



Area patagonica A. oxytropis. 



Pecten proximus P. caracolensis. 



Cardium philippii C. multiradiatum. 



Cardium pisum. . -. C. spharidium. 



Tellina jeguaensis T. promaucana. 



Mactra garretti M. truncatula. 



Sigapatella americana S. colchaguensis. 



Strut] dol aria ameghinoi S. chilensis. 



Tritonium morgani T. verruculosum. 



Urosalpinx elegans U. leucostomoides. 



Fusus torosus F, pyruliformis, 



Thus, out of 151 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 



