| OCR Text |
Show 1886.] SO-CALLED PELV1STEIINUM. 165 millim. Length of ilium 140 Crest 20 Breadth opposite the acetabulum 35 Length of pubis 55 Interpubic bone, antero-posterior diameter .... 15 „ „ breadth of one side 35 In Phacochcerus the bone occupies the position of the triangular ligament in man, and is three-cornered and wedge-like. The following measurements were made :- millim. Length of os innominatum 250 Crest .. 120 Breadth of ilium above acetabulum 32 „ „ at acetabulum 70 ,, ,, below acetabulum 34 Arch of pubis 75 Interpubic bone, breadth 24 „ „ superior depth 15 ,, „ inferior depth 30 „ ,, thickness at base 20 In the skeleton of the Beaver the bone is not so distinct as in Phacochcerus. The following are the measurements :- millim. Length of os innominatum 160 Crest 30 Breadth opposite acetabulum 35 Arch of pubis 75 Depth of pubic bone 9 Breadth of one half 25 I do not find the bone present in any other mammalian skeletons that I have examined. The bone occupies the position of the triangular ligament and the os cloacae of Lacertilians. Ligaments and fasciae are so often the seat of ossifications, and bones in one set of animals are so often represented by ligaments in another set, that one is almost tempted to regard the bones above referred to as, in whole or in part, homologous with the triangular ligament of the urethra found in the higher animals. The interpubic bone in Bradypus is mentioned by Prof. Flower in his 'Osteology.' |
