GENERAL STRUCTURE. 



1255 



which is greatly elongated in some Ungulates (fig. 1 1 2 8 bis), but in 

 the Primates and some other forms there is no such union. In the 

 Monotremata and Marsupialia epipubic, or marsupial, bones are 

 attached to the anterior border of the pubic symphysis (fig. 1139). 

 The femur may have a third trochanter (fig. 1226) for the attach- 

 ment of one of the gluteal muscles. The tibia and fibula are never 

 crossed at their distal extremity, but lie in their primitive parallel 

 position ; the tibia, or preaxial bone, being internal in the usual 

 walking position, and the fibula external. The latter bone may be 

 more or less rudimentary, and completely anchylosed at one or both 



Fig. 112862s. — The left side of the pelvis of the Eland (Oreas cannd). One-sixth natural size. 

 il, Ilium ; is, Ischium ; s, Symphysis of do. ; a, Epiphysis on symphysis of ischium and pubis ; 

 J>b, Pubis ; ob, Obturator foramen. 



extremities to the tibia. The patella is present in all except some 

 Metatheria. If the pes (fig. n 29) be compared with the typical 

 tarsus mentioned on p. 907, it will be found that the fibulare is 

 represented by the calcaneum, which may also contain an element 

 corresponding to the pisiform of the manus ; the astragalus has 

 been usually regarded as the coalesced tibiale and intermedium, 

 but is thought by Dr Baur to correspond solely to the latter ; 

 the ento-, meso-, and ectocuneiform represent the 1st, 2d, and 3d 

 tarsalia ; while the 4th and 5th tarsalia have coalesced to form the 

 cuboids. The centrale persists as the navicular, which may unite 

 with the cuboid. 1 Other modifications occur analogous to those 

 in the carpus ; but in no instance, as already observed, is the joint 

 between the leg and the pes formed on the line between the proxi- 

 mal and distal rows of the tarsus. The metatarsals and phalan- 



1 Dr Bardeleben has pointed out to the writer that in Cryptoprocta there may be 

 a second centrale, which usually coalesces with the ectocuneiform. 



VOL. II. 2 A 



