j8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. ()2 



more of an anthropoid nature. In none, however, barring one adoles- 

 cent Ateles, is there any trace of the hypotrochanteric fossa. 



The exceptional specimen (skeleton no. 984, U.S.N.M.) is, accord- 

 ing to Gerrit S. Miller, Jr., a true Ateles, and from Brazil, and 

 the only specimen from that region in the Museum collections. Both 

 its femora, and particularly the right, show the hypotrochanteric fossa 

 well developed, unmistakable, and very similar to that in human sub- 

 jects. The gluteal ridge is plainly discernible, and there is no third 

 trochanter. The proximal fourth of the shaft is stout and approaches 

 the quadrilateral. The fossa on the right femur measures 11 by 

 2.5, on the left 10 by 2.5, millimeters. It is situated on the posterior 

 part of what here is the lateral surface and is as usual directly adjacent 

 to the gluteal ridge. Except for the conformation of the shaft at 

 this level the fossa is exactly in location, form, and character as in 

 a human femur. It is strange that this should be the only specimen 

 with the fossa among all the Ateles and the other American monkeys 

 examined, but such is the case. 



THE FOSSA IN OLD WORLD MONKEYS 



Hypotrochanteric Fossa in Old World Monkeys 



No. of 

 femora 



Baboons, yuung 2 



adult 12 



Theropitheci, adolescent 2 



adult 2 



Nasalis, adult 2 



Cynopitheci, adolescent 2 



adult 4 



Erythrocebi, subadult 2 



adult 4 



Prcsbytis, adolescent 4 



adult 10 



Macaques," young ^ . . 6 



adolescent 8 



adult 13 



Total 73 



Several varieties. 



I'"oss 



Gluteal ridge none to marked, generally marginal ; third trochanter 

 absent in over 90 percent ; hypotrochanteric fossa, no trace. 



