NO. I THE HYPOTROCHANTERIC FOSSA HRDLICKA I3 



Cercopithecidae : gluteal ridge, replaced or accompanied occasionally by a 

 fossa hypotrochantcrxca ... 



He adds that, in a CcrcopitJiccus sab. and a Papio ham. the fossa 

 takes the form of a groove in these two named specimens. A mere 

 flattening is present in Nasalis larv., a sHght groove in Nas. larv. juv. 

 It sometimes takes the form of a faint pit, with prominent medial lip. 



No fossa was met with in American monkeys and in Prosimiae. 

 In his concluding remarks Appleton accentuates the fact that : 



in this paper no attempt is made at discussing the significance of ridges and 

 of fossae at the site of muscular attachments. Facts established in this paper, 

 however, suggest caution in the employment of the jossa hypotrochantcrica for 



the natural classification of Primates The distribution of fossa and of 



the alternative gluteal ridge (w^hen large, known as a third trochanter) is an 



argument against this assumption Until more is known of a possible 



functional significance for the appearance of a fossa at the site of insertion of 

 M. glutens maximits, it must be precarious to argue as to the nature of that 

 insertion, whether fossa or ridge, in the common ancestor of Hylobates, the other 

 Simiidae and Man. 



The name fossa hypotrochantcrica is conveniently reserved for a fossa, groove 

 or pit at the site of insertion of ilf. gluteus maximus on the femur. 



Among Primates the hypotrochanteric fossa presents considerable variety of 

 situation ; an extreme condition is presented by the large Simiidae. 



Barring a few incidental mentions of the hypotrochanteric fossa, 

 the above is apparently about all that has been said about it. The 

 textbooks of anatomy generally allude to it but go into no details or 

 explanations. How little regard is paid to it may be seen from 

 the following quotation taken from the most recent treatise on 

 osteology : '° 



Examine and compare the gluteal ridge in different bones : in some it is a 

 prominent crest, in others only a broad rough area, and in others again it is 

 represented by a rough fossa (fossa hypotrochantcrica) , or these different aspects 

 may be more or less combined in one specimen. 



SUMMARY OF OBSERVATIONS FROM THE LITERATURE 



The hypotrochanteric fossa was first noted and named in 1883, 

 by Houze. 



It is, in man, a slight to pronounced, nearly vertical, oblong hollow, 

 situated in the lateral portion of the posterior aspect of the upper 

 part of the femoral diaphysis. It differs in man, more or less, both in 

 location and shape, from that in other primates. It exists in close 

 relation with the jrluteal ridge and the third trochanter. 



-"Frazer, J. E., The anatomy of the human skeleton, 3rd ed.. pp. MZ-i-^ 

 London, 1933. 



