7/4 dr. J. murie on MACACUfi cycloims. [June 18, 



than what ohtains in the common Rhesus. As the illustrations show, 

 the above apparently temporary change in the posterior soft parts 

 of the Formosan Monkey is actually correlated with osteological 

 structure of an aberrant kind. 



In this latter species I find that the pelvic bones have a most un- 

 usual curvature in their long axis, certainly very different from the 

 Rhesus and other Macaques. The ilium anteriorly overrides the 

 sacrum far more than is ordinarily the case. Its upper surface is 

 markedly concave transversely, but longitudinally is strongly convex. 

 The inferior or inner face has an outer sulcus, which, reversely, is a 

 prominence in the Rhesus and other species of the genus. The ischial 

 tuberosities are remarkably truncate and pedate. The subpubic 

 angle is short, narrow, and the thyroid foramen large. The brim of 

 the pelvis is of an egg-shaped contour; but the posterior aperture 

 has a figure-of-8 or hour-glass outline, from a more than ordinary 

 inward prominence of the bones opposite the acetabulum. The 

 special feature, however, is the thrusting forwards of the pubes, and 

 partly the ischia, leaving a wide interval, therefore, between the but- 

 tocks and tail. Their sacro-vertebral angle pretty well agrees with 

 that of a Rhesus, which I compared side by side ; but the pelvic 

 angles diverge considerably. In the Rhesus the vertebro-iliac angle 

 is 165°; in the $ Formosan 110°, in the 6 125°. The ilio-pubic 

 angle of the Rhesus is 105°; of the c? and $ Formosan 95°. My 

 figures of the pelvic bones of the latter animals, if compared with 

 those I have given of the Bornean and Japanese Monkeys, convey 

 through the eye the distinctions better than numerical data. 



I shall only add a few pelvic measurements of Macacus cyclopis 

 accessory to the foregoing :— Pffl?alfi Mdp 



in. in. 



Extreme length of the os innominatum .... 4 - 6 5*1 



Conjugate diameter of the pelvis 2*3 2*15 



Transverse diameter of the same 1"6 1*65 



Its oblique diameter 2 - 5 2*2 



My statements may be objected to on the ground that a softening 

 of the bones or other diseased condition is the cause of the abnor- 

 mality from the Rhesus type. It is as well, then, that I should 

 mention that in the female specimen the whole of the skeletal struc- 

 ture is solid, and exhibits no signs of mollities ossium. Further- 

 more, in it the departure from the normal configuration of the 

 Rhesus is most evident. The long bones of the male skeleton, it is 

 true, are more than usually porous and soft ; the pelvis, though, is 

 sounder, but not so firm as to be consistent with robust health. 

 But this very fact supports the idea of the pelvic differentiation being 

 a specific mark, and not due to disease ; for in the latter, where 

 possibly subject to imperfect ossification, the curvilinear figure 

 presently to be spoken of is less notable. 



The general character of the spinal column in this case is better 

 seen in the $ specimen than in the J , simply because it has been 

 retained as a ligamentous skeleton. 



