ART. 1. PRIMATES OF THE FORT UNIOIST GIDLEY. 25 



It is not within the scope of the present discussion to review in its 

 entirety this admirable memoir, much of which is devoted to the ac- 

 curate working out and discussion in masterful detail of many 

 important morphological features of both extinct and modern Pri- 

 mates. It suffices for the present purpose merely to reexamine 

 critically some of the seemingly more important anatomical features 

 discussed by Gregory which characterize the Xotharctinae and relate 

 especially to the question of the affinities of the group. In this re- 

 gard Gregory has described in great detail the structural modifica- 

 tions of the skeletal elements of Notharctus based on the splendid 

 material in the American Museum's collection, and in so doing has 

 estabhshed beyond question the fact that the Eocene Notharctids 

 were true Primates, and that they were still in a relatively primitive 

 or generahzed stage of development. But, in my opinion, he seemed 

 too greatly impressed with the primitive features of the Notharctids 

 and with the many resemblances he found between this group of 

 early Primates and the Madagascar lemurs, and did not consider 

 sufficiently, or has failed to interpret properl}', the special trends in 

 development indicated in the general skeletal structure of the Noth- 

 arctids. This opinion is based on a detailed restudy of the problem 

 in which the evidence presented by Gregory has been carefully con- 

 sidered, while the fine osteological coUections of modern Primates in 

 the United States National Museum, the casts of most of the skeletal 

 elements of Xothardus kindly furnished by the American Museum, 

 and a small amount of actual Noiharctus material in the National 

 Museum have been used for comparison and study. The following 

 comparisons and criticisms are taken up in the order discussed by 

 Gregory. 



A portion of the lower end of a scapula of Notharctus oshorni was 

 described by Gregory (p. 63). Of this fragment he said: '"By far 

 the nearest resemblances of the part preserved are with the lemurs 

 of Madagascar," and stated that the glenoid fossa, as seen from below, 

 is fike a "slender pear," and that "a very similar form is seen in a 

 certain specimen of Lemur mon^oz.'^ He then pointed out differences 

 between it and Cehus, Alouatta, and even Hapale, but did not note 

 the striking resemblance of the Notharctus scapula fragment to the 

 corresponding portion of that of Hapale and Aotus, in which forms 

 this element is still in almost as primitive a stage as in Notharctus, 

 and to which Gregory's description would apply almost equally well. 

 Moreover, Gregory's figure of the Notharctus fragment (fig. 1, p. 63) 

 shows a notch just above the coracoid. This is drawn apparently as 

 though broken, but if, as seems possible, it should prove to be a true 

 notch, it would have an important significance since it is in the exact 

 position of the suprascapular notch of human anatomy. This char- 

 acteristic notch is found in all the South American monkeys, some- 

 times becoming a more or less completely closed foramen as in 



