28 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.63. 



Lepilemur and Lemur are just the differences observed in comparing 

 the Platyrrhini with these lemurs, and again, the characters of these 

 elements in Notharctas are either like or definitely tending toward 

 the South American monkeys rather than the lemurs. For example^ 

 the greater width of the shaft at the lower end, the better develop- 

 ment of the eminences for the attachment of the pronator radii teres 

 on the mid-anterior border of the radial shaft, the less sharply marked 

 interrosseus ridge, the thinner anterior border of the radial shaft, 

 characters noted by Gregory, are all Platyrrhine modifications. To 

 these may be added the greater width of the proximal end of the 

 shaft of the ulna; less curved distal portion of the ulnar shaft; the 

 definitely greater relative distance of the biceps tuberosity below 

 the head of the radius; and the modifications of the distal end of the 

 radius which are definitely tending toward the Platyrrhine type, es- 

 pecially as exemplified in Hapale. In this respect the radius of Hap- 

 ale seems to stand structurally almost intermediate between that of 

 Notharctus and Alouatta.. 



The manus of Notharctus is unquestionably primitive in structure; 

 and, as brought out but not so stated by Gregory, differs as widely 

 from the lemur as from the Platyrrhine manus. For this reason, 

 therefore, the evidence derived from it is largely negative in charac- 

 ter and need not here be discussed in detail. 



In describing the pelvis of Notharctus, Gregory stated (p. 83) ''it is 

 essentially of lemurine type, " and that "it differed in many particu- 

 lars from the pelvis of New World monkeys. Old World monkeys, apes, 

 and man; it is in each case more primitive — that is, very close to the 

 tupaioid or Menotyphla type." Continuing in more detail he stated 

 that "as viewed from below, the opposite halves of the pelvis of 

 Notharctus form a sort of lyre, the blades of the ilia diverging autero- 

 externally beyond the first sacral vertebra," and that "in all lemurs 

 this feature is still more pronounced," while in the New World mon- 

 keys "in the ventral view the opposite ilia are more parallel to each 

 other and do not diverge anteriorly." He noted also the presence 

 in the pelvis of Notharctus of a well-defined anteacetabular spine and 

 other features which he considered lemurine and not anthropoid. 



This presentation seems rather convincing as stated and as illus- 

 trated by the specimens of recent forms selected and figured by 

 Gregory, but I do not find his contentions substantiated by the 

 material I have had in hand for comparison. First of all Gregory's 

 comparisons on the lemur side were evidently made with Madagascar 

 species only, as his statements do not apply in any degree to the 

 Continental or Asiatic lemurs. If such a form as Perodicticus potto 

 is considered, the "lemurlike" characters of the pelvis of Notharctus, 

 noted by Gregory, almost totally disappear. In this Continental 

 lemur (see pi. 5, fig. 6) the ilia are almost straight and rodlike, and 



