188 ■ SHUFELDT. 



is its unusual length as compared with its width; the former being 

 about 8.7 centimeters and the latter 4.3 centimeters taken opposite the 

 acetabulse. 



Its articular surface for the sacrum is upon the inner side of the ilium 

 about 1.7 centimeters from the "crest," and covers an area of a little 

 more than 1 centimeter in length. Dorsally, this area projects as an 

 elongated, sharp crest; otherwise it is entirely conimed to the surface 

 of the ilium proper and is faintly divided into two facets, a long posterior 

 or dorsal one, and a shorter oval one, parallel to and in close contact 

 with it. 



Flower has stated that in " Galea pithe cm" the symphysis pubis "is 

 long, as in the Carnivora, and becomes ankylosed." -'^ He is certainly in 

 error in this statement for in all the specimens before me the symphysis 

 pubis is reduced to the merest contact of the bones, the area being very 

 small, and ankylosis never results. (See figure 14.) As he states, the 

 symphysis is long in most Carnivora, and this can be easily verified by 

 examining the pelvis of any of the Felida3. 



In the articulated skeleton of Oynocephalus the preacetabular portions 

 of the ilia are nearly parallel to each other and lie in a subtransverse 

 plane that makes but a slight angle with the longitudinal axis of the 

 lumbar and sacral vertebrje. The anterior presacral portions of the ilia 

 are directed upward, forward, and outward; the free extremities, which 

 are slightly enlarged and rounded, are about opposite the neural spines 

 of the vertebrae. Thus it will be observed that all the preacetabular 

 portion of the pelvis affords' but very slight protection to the contained 

 abdominal viscera; it does afford protection to some extent laterally, 

 and in conjunction with the sacrum and leading caudal vertebrae, to a 

 greater extent dorsally. 



It remains to say of the preacetabular part of an ilium that it is 

 sigmoid in form, and for the most part subcylindrical, although exhibit- 

 ing slight longitudinal flatness dorsally, mesially, and externally. This 

 rod-like part of the ilium gradually expands as it comes to the acetabulum 

 which it assists in forming. The latter is large, being over 1 centi- 

 meter in diameter, and presents all the usual mammalian characters. 

 Its cotyloid notch is wide and rather deep ; the cotyloid articular ring 

 is well developed; while the bone, at the bottom of the cavity is often 

 very thin and always translucent. As usual, it is formed by the three 

 pelvic bones, the ilium, the ischium, and the pubes, the sutures among 

 which have become entirely obliterated within the cotyloid cavity. In 

 fact the only sutural line that persists throughout the life of the in- 

 dividual among any of the three pelvic bones is the one between the 

 rami of the ischium and pubes. It is very distinct in all specimens at 

 hand, and probably is invariably present. (Figure 14.) 



-' Osteology of the Mammalia, 320. 



