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PATAGONIAN EXPEDITIONS: PALAEONTOLOGY. 
Litopterna, making it the type of a family, at first called Protequidae 
(’9P, 135), subsequently Notohippidae (’94*, 27). Later, he assigned the 
family to his new order Hippoidea and regards it as closely related to 
the true horses (’04, 33). With this view I am not able to agree, being 
of Roth’s opinion that the Notohippidae are of toxodont affinities (’03, 
33). The molar pattern is typically toxodont and, as Roth points out, 
the structure of the auditory region, at least in the pre-Santa Cruzian 
genera, is also that of the toxodonts. Whether the family is referable to 
the suborder Toxodonta, or not, is not yet entirely clear, though I am 
inclined to believe that it should be so referred, as has been done by 
Schlosser (T 1, 519). 
