508 ANATOMY OF VERTEBRATES. 



In the plantigrade Carnivora the clavicle is wholly wanting. 

 In the Bear-tribe, the scapula, fig. 336, si, is remarkable for its 

 almost quadrate form, and for the strong development of the 

 ridge between the infraspinatus and teres major, constituting 

 almost a second spine. The inner condyle of the humerus is not 

 perforated, save in Ursus ornatus. The antibrachials little, if at 

 all, exceed the humerus in length ; their shafts are of equal 

 strength. The scaphoid and lunar bones of the carpus have 

 coalesced: the pisiforme is elongated and expanded at its free 

 end like a calcaneum. The fore-foot is 5-dactyle, the pollex 

 being a little shorter than the other toes, Avhich are subequal in 

 length ; the basal sheath of the ungual phalanges is thickened 

 and tuberculate below : the claw-bearing part is long, subcom- 

 pressed, and slightly arched. The ilia are shorter, thicker, and 

 broader than in Digitigrades : the ischia are short and expanded, 

 forming with the strong pubics a long symphysis. The acetabula 

 are large and deep ; the ilio-pubic angle is 125°. The femur is 

 remarkable, in Bears, for its great length, and superficial resem- 

 blance to that in man ; but its shaft is relatively thicker, 

 straight er, and rather flattened from before backward ; it differs 

 also in the more shallow pit for the round ligament, in the great 

 trochanter being longer though less prominent above, in the less 

 projection of the small trochanter, in the minor expansion of the 

 distal condyles, and in the smaller size of the rotular channel. 

 The medullary cavity is confined to the middle third of the bone. 

 The medullary artery, which enters at the posterior and inner 

 side, below the middle of the shaft, takes an oblique course up- 

 ward. The tibia is one-fourth shorter than the femur : the fibula 

 is much smaller and compressed : but the medullary cavity ex- 

 tends through nearly the whole of the shaft of this slender bone. 

 In fig. 174, cl marks the calcaneum, s the naviculare, e the ecto- 

 cuneiform, h the cuboides ; the astragalus is almost as broad as 

 long, mthout a calcaneal process. The hallux is rather shorter 

 than the other toes, which are of subequal length, and form the 

 basis of a broad flat foot. 



In the scapula of the Kacoon {Procyon), the pre- and post- 

 spinal fossae are of equal extent. The inner condyle of the 

 humerus is perforated as in all Subursines. In Nasua and Arc- 

 tictis, a supplementary carpal ossicle is wedged between the scaplio- 

 lunar and the metacarpal of the pollex, external to the trapezium : 

 the tarsus shows a corresponding ossicle wedged between the 

 naviculare and entocuneiform. In the Kacoon, the fibula is 

 characterised by three processes behind its distal end : the malle- 



