420 \V. K. GREGORY NOTHARCTUS AND LEMUROIDEA 



Marsh, who described a similar jaw fragment the next year, 1871, 

 also noted its resemblances to the supposed suilline pachyderm Hyopsodus. 

 In October, 1872, however, Marsh described some better specimens, which 

 included parts of the limb bones. He remarked that the principal parts 

 of the skeleton of these animals were formed much as in some of the 

 Lemurs, especially the limb bones, and he referred the animals to the 

 order Quadrumana. He also gave the correct dental formula. The 

 subsequent systematic history of the group was developed by Cope, Marsh, 

 Osborn, AVortman, and ^Matthew in a long series of papers, extending 

 from 1871 to the present time. Through tlu'ir hibors three valid genera — 

 Pelycod'us, Notharctus, and Telnialt'stes — inchidiug perhaps a dozen or 

 more nominal and valid species, have been recognized, constituting the 

 family Limnotherida? of Marsh, or JSTotharctidie of Osborn. 



The prohknu of the relationship of this family to other Eocene fam- 

 ilies, namely, to the Hyopsodontidae, to the Adapidaj of Europe, and to 

 the modern Lemurs, has had a confusing history. Marsh, as it now 

 seems, correctly placed the group as Ijeing moi'e or less related to the 

 modern Lemurs. Cope was long deceived by a false association of 

 Creodont claws with teeth belonging to Pelycodus, and on this miscon- 

 ception ho based his suborder Mesodonta (1876). This error was cor- 

 rected both by Schlosser (1887, page 22) and by Matthew. Cope also 

 held that the genus Notharctus and its allies were related to the European 

 Eocene genus Adapis, and he referred them all to the family Adapidte 

 (1885). 



Osborn, in 1902, revised the genera and species of American Eocene 

 Primates, defined the family Xotharctidip, and traced the history of the 

 family from the Lower Eocene species of Pelycodus to the Upper Middle. 

 Eocene species of Telmalestes. Up to this time these animals were 

 known chiefly from the dentition, and as Professor Osborn did not regard 

 such material as adequate, he left unsettled the general problem of the 

 relationships of this family, provisionally retaining them in Cope's group 

 Mesodonta. 



Wortman, in 1904, endeavored to show that the Hj^opsodontidge, which 

 had been supposed to be related to the N'otharctidae, were not Primates 

 at all, but Lisectivores. He regarded Cope's Mesodonta as an unnatural 

 assemblage. He placed Notharctus with the European genus Adapis in 

 the Adapidae, but he regarded this group as not at all nearly related to 

 the modern Lemurs ; he thought rather that the Adapidse stood near to 

 the beginnings of the higher Primates, especially the New World 

 monkeys. Accordingly he placed Notharctus, along with Adapis, in the 

 same division with the monkeys both of the New and the Old World, 



