114 



gkegoky: notharctus, an American eocene primate 



centrum and are directed outward and downward, whereas in Macacus they are smaller, spring from 

 points higher up on the sides of the centra, or even from the bases of the neural arches, and are less inclined 

 downward. In Cebus the transverse processes are on the whole more like those of Macacus than like 

 those of Lemur. In Alouatta they spring almost from the base of the neiu'al arches. The lumbars of 

 the marmosets may be regarded as modifications of the primitive lemurine type, l^ut the neural spines 

 and transverse processes are more delicate. 



Fig-. 2S. IVIvi.s and vc-rtdmo of Ilajxilr jiirrhu.s. Amw. Tvlus. No. 17.")74. Latmil and ventral aspects. X f. 



Musculature of the Lumbar Region. — The form of the lumbar centra of Notharcius and Lermir, 

 which are elongate, narrow and vertically shallow, are associated with a more horizontal pose of the 

 body in resting; while the short, broad and vertically shallow lumbar centra of Macacm are associ- 



